I have to create a program in C and I can't figure it out. The program has to read a source file. Please help.

/******************************************************************** PROJECT: Glossary

FILE: glossary.c

DESCRIPTION: A program that reads, writes, and maintains a simple glossary of terms and definitions.

REQUIREMENTS: R01 User is prompted for action (code provided), or given the option to exit the program.

R02 The first term containing the search string is the entry that is displayed to the user.

R03 Terms are to be maintained in alphabetical order.

R04 If the user selects [R]ead from file, existing glossary entries shall not be overwritten.

R05 If the user selects [S]ave to file, and the file exists, the user shall be warned before overwriting the file.

DESIGN Significant Variables --------------------- struct item { char term[25]; char defn[255]; }; struct item glossary[MAX_ITEMS];

Algorithm --------- A00 Prompt user for selection; A05 If (valid entry) { Call corresponding function call; } A10 Else { Prompt again; } A15 Prompt user to save work A20 Return 0; ********************************************************************/

#include #include #include

/* Definitions */ const int MAX_TERM_LEN = 25; const int MAX_DEFN_LEN = 255; const int MAX_ITEMS = 500;

struct item { char term[25]; char defn[255]; };

/* Function prototypes */ int addEntry(struct item[]); int deleteEntry(struct item[]); int searchEntry(struct item[]); int readFromFile(struct item[]); int saveToFile(struct item[]);

int main() { /* Declarations */ char action;

int numItems, result;

struct item glossary[MAX_ITEMS];

/*L00*/ /* Prompt loop */ printf("[A]dd, [D]elete, Searc[H], [R]ead from file, [S]ave, [E]nd>"); scanf("%c", &action); fgetc(stdin); /*L05*/ while(action != 'E') { if(action == 'A') { result = addEntry(glossary); if(result < 0) { printf("Entry exists! "); } else { printf("Add entry successful. "); } } else if(action == 'D') { result = deleteEntry(glossary); if(result < 0) { printf("Entry does not exist! "); } else { printf("Delete entry successful. "); } } else if(action == 'H') { result = searchEntry(glossary); if(result < 0) { printf("Entry not found! "); } } else if(action == 'R') { result = readFromFile(glossary); if(result < 0) { printf("Error reading from file! "); } else { printf("Read successful. "); } } else if(action == 'S') { result = saveToFile(glossary); if(result < 0) { printf("Error saving to file! "); } else { printf("Save successful. "); } } /*L10*/ printf("[A]dd, [D]elete, Searc[H], [R]ead from file, [S]ave, [E]nd> "); scanf("%c", &action); fgetc(stdin); } /*L15*/ printf("Do you want to save your work before exiting? (Y or N)> "); scanf("%c", &action); fgetc(stdin); while(action == 'Y') { result = saveToFile(glossary); if(result < 0) { printf("Error saving to file! "); } else { printf("Save successful. "); printf("Exiting the applicaiton. "); exit(0); } printf("Do you want to save your work before exiting? (Y or N)> "); scanf("%c", &action); } printf("Exiting the application. "); /*L20*/ exit(0); }

/******************************************************************** DESCRIPTION - addEntry Adds a new entry to the existing glossary

REQUIREMENTS: R01 Entries are added in alphabetical order

ALGORITHM: A100 Prompt user for term, definition; A105 Search glossary for existing term; A110 If(term exists) { Return -1; } A115 Else { Move all terms down in glossary array starting at the last term that was lexically less than the search term; Add new search term in the now empty array position; Increment numItems by 1; Return 0; } ********************************************************************/

int addEntry(struct item entries[]) { return -1; };

/******************************************************************** DESCRIPTION - deleteEntry Delete a term and its associated definition

REQUIREMENTS: R01 Entries are maintained in alphabetical order

ALGORITHM: A200 Prompt user for term; A205 Search glossary for existing term; A210 If(term exists) { Delete item from array Move all items in glossary array up by one position; Decrement numItems; Return 0; } A215 Else { Return -1; } ********************************************************************/

int deleteEntry(struct item entries[]) { return -1; };

/******************************************************************** DESCRIPTION - searchEntry Search for a term, and display both the term and the definition if found

REQUIREMENTS: R01 Entries are maintained in alphabetical order

ALGORITHM: A300 Prompt user for term; A305 Search glossary for existing term; A310 If(term exists) { Display term and definition; Return 0; } A315 Else { Return -1; } ********************************************************************/

int searchEntry(struct item entries[]) { return -1; };

/******************************************************************** DESCRIPTION - readFromFile Read in terms and definitions

REQUIREMENTS: R01 Entries are maintained in alphabetical order

R02 Input text file is formatted as provided

R03 File opens without error

ALGORITHM: A400 Prompt user for filename; A405 Open file; A407 If(file open error) { Return -1; } A410 While(!EOF) { A415 For(each item in file) { Search for term in existing glossary array A420 If(item does not exist) { Add term to glossary array; Increment numItems; Continue; } A425 Else { Continue; } } A427 Close file; A430 Return 0; ********************************************************************/

int readFromFile(struct item entries[]) { return -1; };

/******************************************************************** DESCRIPTION - saveToFile Save glossary array to file

REQUIREMENTS: R01 Entries are maintained in alphabetical order

R02 Output text file is formatted as provided

R03 File opens without error

R04 The produced file can be read back in by readFromFile()

ALGORITHM: A500 Prompt user for filename; A505 Open file; A507 If(file open error) { Return -1; } A510 For(each item in glossary array) { Write to file; } A515 Close file; A520 Return 0; ********************************************************************/

int saveToFile(struct item entries[]) { return -1; };

The source file:

128-bit and higher encryption (strong encryption) - Currently one of the strongest encryption schemes used for secure Web page transmission.

40-bit encryption (weak encryption) - Encryption scheme that is too weak for secure Web page transmission.

56-bit encryption (medium-level encryption) - Intermediate-level strength encryption scheme for data communications.

64-bit encryption (medium-level encryption) - Intermediate-level strength encryption scheme for data communications.

absolute positioning - When an HTML layer (a DIV element) is positioned on the page using the upper left-hand corner of the page as a reference point.

absolute URL - A hyperlink to a Web page on a different Web server.

acceptable use policy (AUP) - Usage restrictions for computer accounts, Internet access accounts, and many other Internet-related services.

ActiveX - A set of technologies developed by Microsoft that allow different application software programs to communicate with each other. ActiveX controls represent a specific way of implementing and using these technologies; in this book they are discussed in the context of software installation.

add-on - An application that works alongside and complements another application.

address harvester - See e-mail harvester .

address space - The range of addresses that a specific central processing unit (CPU) can reference.

Addresses - Specific memory locations.

Adware - Any software application that displays advertisements.

Aggregator - See RSS client.

AIM - AOL Instant Messanger.

AJAX - A programming technique that uses Asynchronous JavaScript, CSS, and XML to create Web application software.

Algorithm - A sequence of instructions used to solve a problem.

Alias - An alternative name for a host machine, a server name, or an e-mail address.

Alpha - A Pre-release version of a software application. Some features may not be implemented and others may be buggy. Released primarily for testing and evaluation.

anchor tool - Composer tool used to place link targets on a Web page.

Anonymizer - An Internet service that protects the identity of its subscribers by giving them a working alias for all of their online communications.

anonymous FTP - Protocol used to allow guest access to an FTP server. By default, the account name is anonymous and the password is the e-mail address of the guest user.

anonymous remailer - An e-mail account designed to protect the identity of its owner.

antivirus software - Software used to scan incoming files and remove harmful software.

Applet - See Java applet.

application - See application software.

Application Service Provider (ASP) - A provider that makes standard office applications available on Web servers.

application software - A special-purpose computer program that addresses a specific computing need .

Arguments - A list of values or variables found in a function call, usually as the value of an event attribute.

ASCII character code - The American Standard Code for Information Exchange, which encodes 128 characters.

ASCII characters - Alphanumeric characters and other printable symbols normally found on a computer keyboard.

ASCII text file - A file that contains only ASCII characters. ASCII text files can be displayed and opened by text editors (unlike binary files).

ASP - See Application Service Provider.

assignment statement - A command in some programming language that assigns a value to some object, usually a variable.

asymmetric encryption - See public-key encryption

Atom (syndication format) - A protocol for publishing Web-based content.

AUP - See acceptable use policy.

Authentication - Protocol used to confirm the identity and permissions of a user accessing some computer service.

authoring tool - A utility that is used to customize a script.

automated link checker - A utility that automates link maintenance.

Bandwidth - Related to the data transmission rate over a given communication channel. High bandwidth channels can support high data transmission rates.

Baud - A measurement of transmission rates of electrical signals (often confused with bits per second ).

Beta - A nearly complete version of some software product that is ready for end users to review.

binary file - A file that contains unprintable characters such as control characters. Binary files cannot be dis played or opened with text editors.

Bit - A memory unit that can hold one of two possible values: 0 or 1.

bits per second (bps) - A measure of the rate of data exchange between computers.

Blog - An online journal or diary, also known as a Web log.

Bookmark - A pointer to a Web page that you expect to revisit. Internet Explorer calls them Favorites instead of bookmarks.

Boolean operators - The logical operators AND, OR, and NOT. Usually supported by search engines that offer an advanced query option.

Boolean query - A search-engine query that uses Boolean operators.

bot network - Usually refers to a group of computers under clandestine control of some remote operator, usually for nefarious purposes, like distributing worms and viruses.

botnet - See bot network.

bps - See bits per second.

broadband channel - A high-bandwidth connection.

broadband connection - A communication connection that supports many channels.

browser add-on - An application that works alongside and complements a Web browser.

browser cache - A location on disk where files for Web page displays are saved for some period of time.

browser helper application - See helper application .

browser plug-in - See plug-in.

browser-specific extensions - Unofficial HTML tags and attributes that are supported by only one Web browser.

browsing - The process of reading Web pages and traversing links to more Web pages. Browsing can be goal-oriented or purely recreational.

buffer - A temporary holding area in which a portion of a file is held during a download.

built-in functions - A set of previously written functions in some programming language used as programming tools to accomplish commonly required tasks.

bulletin board - See message board.

bursty - Used to describe traffic that ebbs and surges on the Internet.

byte - A unit of computer memory containing eight bits.

CA - See certificate authority.

cancelbot - A program that detects spam on the basis of multiple postings and to issue a Cancel command.

Cascading Style Sheet (CSS) - Used to specify the appearance of Web page elements.

central processing unit (CPU) - The part of a computer that executes machine instructions to run a computer program.

CERT - A government-sponsored reporting center for Internet security problems.

certificate authority (CA) - A trusted third-party organization or business that issues digital certificates.

CGI - See Common Gateway Interface.

clear signature - A digital signature embedded in a clear (unencrypted) document.

clearinghouse - An exhaustive collection of online resources for a specific topic.

clear-signed document - An unencrypted document containing a digital signature.

client - An Internet host that consumes information from the Net.

client/server model - A de facto standard for network-oriented computing; client-server interactions underlie all communication on the Internet.

clock speed - A measure of the central processing unit (CPU) that determines how many instructions (simple computer operations) the CPU can execute in a fixed period of time.

clustering - A technique used by some meta search engines that groups hits to simplify navigation.

color palette - A collection of colors used in Web construction.

color sampler - A computer program that allows you to determine the hexadecimal code for any color on your computer screen.

Common Gateway Interface (CGI) - A standard interface through which a program on a Web server interacts with Web pages in real time.

communication protocol - A common language that computers share.

compiler - A program that translates an application written in some programming language into the machine language of the computer that will execute it.

compression - See file compression .

computer virus - See virus.

construction kit - See Web site construction kit .

container element - An HTML element that requires a start and an end tag.

contextual selectors - A method of limiting the range of a CSS rule to specific HTML elements only when they appear in conjunction with certain other HTML elements.

controls - See form control elements.

cookie - A small piece of text generated by a site's Web server and stored on a host machine by a Web browser; it is made available to the originating server on demand whenever the host machine downloads Web pages from that Web server.

cookie manager - A software application that makes it easy to set cookie accept/reject policies for different Web sites.

copyleft - Using copyright law to allow distribution by others of copies and modified versions of a work coupled with the requirement that the same freedoms be preserved in modified versions.

copyright - A legal claim of ownership that applies to original text, photographs, artwork, and musical works.

copyright infringement - An unauthorized use of copyrighted materials that could lead to a lawsuit if the copyright holder wants to prosecute.

CPU - See central processing unit.

cryptography - The study of coding systems used to protect information and secure sensitive communications.

CSS - See Cascading Style Sheet .

cycle - The smallest unit of time recognized by a computer's internal clock.

Dark Web - Refers to information stored on computers that are not connected to the Internet or are otherwise unreachable.

data alteration - The interception of data sent from a browser to a Web server in the clear (i.e., unencrypted) and alteration of that data en route, either maliciously or accidentally.

data rate - The rate of data transmission.

data width - See word size.

decoding - The process of unscrambling a coded file or message.

decrypting - See decoding.

Deep Web - Refers to information stored on computers that are, intentionally or not, hard to find.

denial-of-service attacks - Attacks perpetrated by hackers in which targeted Web sites experience crippling numbers of packet requests, shutting out general users.

derivative work - Any image derived from the original via manual or automated modifications.

device driver - Software that creates a communication link between a computer and a peripheral device so that data can ow smoothly between the two.

DHTML - See Dynamic HTML.

digital certificate - A document on a Web server that can be checked to verify the identity of the server.

digital fingerprint - A sequence of hexadecimal numbers associated with a key pair that can be used for key authentication.

digital signature - An encoding of a document with a private key to preserve document integrity and document ownership.

directory - A file directory. Also a synonym for subject tree and topic hierarchy .

discussion board - See message board.

discussion group - See message board.

disk optimizer - A utility that analyzes a hard drive and reorganizes the files stored there in order to eliminate fragmented files.

DIV element - Used to create an HTML layer.

DNS address - See Domain Name Service address.

doctrine of fair use - A legal guideline that allows writers and scholars to quote excerpts from other works.

domain hack - A clever use of characters used to devise a domain name, like del.icio.us.

domain name servers (DNSs) - Internet hosts that translate DNS addresses into IP addresses on demand.

Domain Name Service (DNS) address - A symbolic host address that can be translated by domain name servers into an equivalent IP address.

dots per inch (dpi) - A measure of print resolution, often confused with computer monitor resolution (ppi); a good printer has a resolution of 300 dpi, whereas a good monitor displays only 7296 ppi.

double-key encryption - See public-key encryption.

download - To move a copy of a file from a computer at a remote location to your local computer. A Web browser downloads Web pages from a Web server so they can be displayed by the local host running the browser. See also upload .

download manager - Software that facilitates file downloads from Web pages and FTP servers.

dpi - See dots per inch.

drop-down menu - An HTML SELECT element.

Dynamic HTML (DHTML) - Web content that can change each time it is viewed.

dynamic routing - A strategy for finding the best pathway between two hosts, given current conditions on the Net.

electronic mailing list - A collection of e-mail addresses used to distribute a single message to multiple recipients.

Electronic Privacy Information Center (EPIC) - A clearinghouse for all Internet-related privacy concerns.

e-mail - Electronic mail; the most popular software application on the Internet.

e-mail address - An address of the form @.

e-mail attachment - A file that is sent to an e-mail address as an optional addition to a plain text message body. E-mail attachments can be either ASCII text or binary files (unlike e-mail message bodies, which can only contain ASCII text).

e-mail client - Software that can transfer e-mail messages between a local host and a local e-mail server, as well as display and compose messages on the local host.

e-mail harvester - A computer program that explores public resources on the Internet and collects active e-mail addresses.

e-mail server - Software that can send e-mail messages to and receive e-mail messages from other e-mail servers, as well as hold incoming messages for local e-mail clients.

emoticons - A symbolic system for expressing simple emotions in ASCII text; for example, :-) is the smiley.

empty element - An HTML element that does not use an end tag.

empty string - A string that contains no characters, usually indicated by a pair of single or double quotes, with nothing in between.

encoding - The process of transforming a message or file into an unreadable form.

encrypting - See encoding.

escape character - The backslash character, used to change the way the browser or an interpreter will treat the character that follows it.

escape sequence - The backslash character plus one other character, used to insert special characters or commands into a string.

escrow service - A service associated with e-commerce that will withhold a buyer's payment from an online seller until the buyer has received the item and deemed it acceptable.

event - User-initiated action such as pressing a key, clicking a mouse, or moving a mouse.

event attribute - Required to endow HTML elements with the capability to respond to user-initiated events.

event handler - A computer program that is executed when a specific event occurs.

exact phrase matching - A technique used by search engines to locate documents containing words in a specific sequence; the query phrase is treated as a single keyword.

executable code - Computer code that can be interpreted directly by the hardware.

Extensible Hypertext Markup Language (XHTML 1.0) - A new Web page standard intended to replace HTML.

FAQ - A file of frequently asked questions, originally associated with Usenet newsgroups.

fast memory - See random access memory.

file - A collection of data that has a name (a filename).

file archive - A single file that contains several other computer files, usually in a compressed format.

file archive utility - A program used to open a file archive.

file compression - A strategy for minimizing the amount of memory needed to store the contents of a file.

file converter - A computer program that allows you to convert a file in one format into a different file format.

file extension - A (usually) three-letter code used to identify the format associated with some file.

file header - Hidden housekeeping information inserted into a file by the application that created it.

File Transfer Protocol (FTP) - An Internet protocol that makes it possible to transfer files between two host machines.

filename - The name associated with a file .

filtering (e-mail) - A way of handling messages based on specific words in their subject headers, from fields, or message bodies.

firewall - A software application that protects your computer from hacker attacks and intruders; it monitors all networked communications in order to detect unauthorized access.

first-party cookie - A cookie created by the Web server hosting the current Web page; compare to third-party cookie.

ame - An e-mail or newsgroup message in which the writer attacks another person with open hostility.

ame war - An exchange of ames between two or more participants.

oating-point unit (FPU) - A special microprocessor designed to handle oating-point arithmetic, crucial for speedy graphics displays.

FLOSS - Free-Libre/Open Source Software.

folksonomy - A Web-accessible database with content organized by its users via tagging.

form control elements - Includes buttons, radio buttons, check boxes, text input boxes, text areas, select lists, and other elements that are used to facilitate implementation of interactive capabilities on Web pages.

Form element - An HTML element that must be used to contain all form control elements.

format command - A set of characters that tells the computer how to display the contents of the associated variable.

format string - A string to be printed out by some computer program that may contain format commands.

forum - See message board.

FPU - See oating-point unit.

fragmented file - A file that does not occupy contiguous space because it has been spread across small blocks by the operating system.

fragmented hard drive - A hard drive that has many fragmented files.

frame - A device that allows you to partition a Web page into multiple segments so that you can display a different HTML file within each segment.

freeware - Software that is distributed free of charge.

frequency count - In selective-text indexing, the number of times a word appears in a document.

FTP - See File Transfer Protocol.

FTP client - A software application that is used to transfers files to and from an FTP server.

FTP server - A computer that manages files.

full-text indexing - A database indexing technique used by search engines in which all the words of a document are used to index that document.

gateway pages - Web pages tuned for different search engines that link back to the main site.

general search engine - A search engine that indexes a large collection of Web pages via keywords.

GIF - See Graphics Interchange Format .

gigabyte (GB) - A unit of computer memory containing 1,024 megabytes.

gigahertz (GHz) - A unit used to measure processor speed; 1 billion cycles per second.

graphics editor - A computer program that allows you to alter an image during Web page construction.

Graphics Interchange Format (GIF) - A file format used for line art, cartoons, and simple images on the Web.

group reply (or reply-to-all) - An e-mail reply that goes to both the message author and everyone included in the To: and Cc: fields; compare sender-only reply.

guest telnet session - Limited telnet access to a host that is open to the general public.

h2g2 - An alternative Web Encyclopedia.

hacker - A person who searches for and exploits security holes found on Internet hosts. Also, someone who is capable of finding clever and original solutions to computer programming problems.

hash code - An algorithm that maps text into a sequence of digits. One-way hash codes (codes that cannot be reversed) are used to store computer passwords and create digital signatures.

helper application - An application that can be launched by another application.

heterarchical network - A network in which the nodes are interconnected randomly, with no node occupying a position of greater importance than any other node.

hexadecimal notation - A notational system for the base16 integers that uses digits 09 and letters AF.

hidden text - Text on a Web page that is not displayed by Web browsers but is used by search engines.

hierarchical network - A network that is organized in the shape of a pyramid and that includes a unique root node that is superior to all other nodes.

history list - A list of all clickable links to all the Web pages you've visited recently.

host address - An IP or DNS address used for Internet communications.

host machine - Any computer that maintains an active Internet connection.

host name - A short alphanumeric name given to a computer to differentiate it from other computers in its local area network.

hot spot - See hotzone.

hotzone - A defined region on a Web page image that contains a hyperlink.

HTML attribute - An attribute is used to provide further details regarding the display of an HTML element.

HTML converter - A Web page construction tool that takes a text document in non-HTML format and converts it to an HTML file.

HTML element - A segment of an HTML file that is interpreted and rendered by a Web browser in accordance with an HTML standard.

HTML - See Hypertext Markup Language.

HTML source file - The text file downloaded by a Web browser and used to display a Web page.

HTML tag - A marker within an HTML file that delimits an individual HTML element. All HTML tags appear inside angle brackets. For example,

is the HTML tag that marks the start of a paragraph.

HTTP - See Hypertext Transfer Protocol .

hyperlinks (or links) - Clickable HTML elements that direct the Web browser to display a different Web page or a different location on the current Web page.

hypertext - A document that contains hyperlinks.

Hypertext Markup Language (HTML) - The markup language used to format Web pages. HTML gives Web page authors control over what a Web browser can and can't do when it displays a Web page.

Hypertext Transfer Protocol (HTTP) - A Web-based communication protocol; used to specify URLs for Web browsers.

ICANN - A nonprofit organization created in 1998 to expand and manage the domain name system.

ID attribute - An HTML attribute used to assign a label to some element.

identity theft - Using stolen personal information to open credit card or other accounts for illegal purposes.

image map - A way to create hyperlinks inside graphical elements.

image mapper - A software utility that generates an entire MAP element based on the information you give it.

image viewer - A computer program that displays graphics files quickly and easily.

IMAP - See Internet Message Access Protocol.

inbox - A collection of recently received e-mail messages waiting to be read.

indexed color - Technique used to reduce the storage requirements of a color image by using a limited color palette.

information retrieval (IR) - A branch of computer science focused on finding information in large text databases.

inheritable - When a CSS rule from a containing element is applied to the contained element.

inline code - Computer code that is placed directly in an HTML file rather than a separate file.

inline image - An image positioned inside a text file as if it were a single oversized character.

inline style - When a STYL E attribute is used to specify style information for an HTML element.

installer - A setup utility used whenever a computer program requires multiple files in order to operate.

instant messaging (IM) - Private communication channels between people who use the same IM client software. Typically used by people who know each other and want to stay in close touch.

instruction set - The collection of operations that the central processing unit (CPU) can execute; also called machine instructions.

intellectual property rights - A broad category of legal protections that includes the protection of patents and trademarks.

intelligent concept extraction - An information-retrieval strategy used by some search engines that automatically augments a query with synonyms and related terms.

interlaced GIF file - A GIF file that displays in increasingly sharper detail while the image is being downloaded by a Web browser.

internal page link - A hyperlink that changes the display to a different part of the Web page that contains the link. See also named anchor .

Internet - A global network of networks (the word stands for inter - networked net - works).

Internet host - See host machine.

Internet Message Access Protocol (IMAP) - An e-mail protocol that stores incoming mail on a mail server.

Internet Protocol (IP) - A communication protocol adopted as a universal addressing system for all computers on the Internet.

Internet Protocol (IP) address - A unique numerical address assigned to each Internet host. All IP addresses consist of four integers separated by periods.

Internet Relay Chat (IRC) - A client-server application that supports real-time chat for multiple participants.

Internet Service Provider (ISP) - A company that provides access to the Internet. ISPs can be based on phone-line connections, DSL lines, or other means of establishing a connection.

Internet telephony (or IP telephony) - A system that allows users to place long-distance telephone calls over the Internet.

intranet - An internal computer network carefully segregated from all external computer networks such as the Internet.

Invisible Web - Refers to Web content that is contained as databases as opposed to residing on standalone Web pages.

IP address - See Internet Protocol address .

IRC - See Internet Relay Chat .

ISP - See Internet Service Provider .

Java applet - A small Java program that is attached to a Web page; can often be used by nonprogrammers.

Java Virtual Machine (JVM) - A platform-specific browser add-on that makes it possible for Web browsers to execute Java applets.

JavaScript interpreter - The browser component that reads JavaScript and causes the specified actions to be performed.

Joint Photographic Experts Group (JPEG) - A group that develops standards for storing images in digital file format (among other things). Sometimes also used as a file extension ( .jpeg or .jpg ).

JPEG (or JPG) - An image file format especially well-suited for posting photographs on the Web. See also Joint Photographic Experts Group .

key authentication - The general process of verifying the owner of a public key.

key certification - The process of placing a digital signature on a public key in order to vouch for its authenticity (a form of key authentication).

kilobyte (KB) - A unit of computer memory containing 1,024 bytes. Sometimes abbreviated K .

layer - See DIV element.

libel - Any written or pictorial statement that damages a person or an organization.

license - An authorization granted by the holder that allows the grantee to use copyrighted work (software program or other intellectual property).

Link element - Used to create various types of hyperlinks.

links - See hyperlinks.

listserv - A mailing list server.

literal strings - A set of characters delimited by single or double quotes.

local area network (LAN) - A network of computers that spans a limited geographical region; used by large companies for in-house data processing.

lossy compression - Compression techniques that reduce the amount of memory required by an image in exchange for some degradation in the image quality.

lurk - To subscribe to a mailing list and read posts without ever posting a message of one's own.

machine instructions - See instruction set.

macro - A small program that allows users to collapse a frequently used command sequence into a single command for greater convenience and efficiency.

macro virus - A virus written inside a macro, which typically executes as soon as the document containing the macro is opened.

mail folder - A folder for e-mail correspondence.

mail server - See e-mail server.

mailing list - A discussion forum in which a large number of people maintain an ongoing dialog that is communicated to every list member through e-mail messages.

main memory - See random access memory.

markup language - A way to insert enhancements into an ASCII text file so that appropriate display software (like a Web browser) can render the file as specially formatted text or text with special effects and graphics.

megabits per second (Mbps) - A data transmission speed, used to measure cable connections.

megabyte (MB) - A unit of computer memory containing 1,024 kilobytes.

megahertz (MHz) - A unit that refers to 1 million cycles per second.

memory leak - A programmer error that occurs when memory requested by an application (or the OS) is not recycled for further use.

message board (or forum) - A Web page where people can read messages, post messages, reply to messages, and track discussion threads.

META element - An HTML element used to insert housekeeping information into the Head of a Web page.

meta search engine - A Web page that enables users to send one query out to multiple search engines for simultaneous processing.

meta-data - Housekeeping information inserted into a file that describes the file contents and organization.

microprocessor - The hardware unit that houses the central processing unit (CPU) in a personal computer.

MIME - See Multipurpose Internet Mail Extension.

MIPS - Million instructions per second; a measure of CPU speed.

mouseover - The action of sweeping the mouse over a region on a Web page that has been programmed to respond to the mouse's presence.

MP3 (MPEG audio layer 3) - A format that can be used to reduce audio files by as much as 90 to 93 percent.

multiplexing - Data throughput that relies on simultaneous data transmissions over multiple channels.

Multipurpose Internet Mail Extension (MIME) - A mail protocol globally recognized as a standard for encoding non-ASCII files as text for reliable transport across the Internet. Almost all e-mail clients support MIME file attachments.

nagware - Shareware that continues to launch after the free trial period is over, but with reminders that it's time to register.

named anchor - A hyperlink to another location on the current Web page.

NaN - Code displayed when a mathematical operation performed by a computer produces a non-numerical valueNot A Number.

Net - The Internet.

netiquette - Standard rules of courtesy for online communication.

netizen - An informed and responsible user of the Internet.

netspeak - A telegraphic style of writing designed to minimize keystrokes through the liberal use of acronyms (e.g., LOL for laughing out loud) and emoticons.

newline character - An escape sequence used to start a new line: .

news client - See news reader.

news reader - Client software for reading and posting to Usenet newsgroups.

newsgroups - A Usenet news group dedicated to a specific topic.

nickname - Aka e-mail alias.

nodes - Members of a network.

one-click shopping - A convenient service designed to speed shoppers through an online purchase; the shopper's account information is protected by a password.

online forums - See message boards .

open source software ( OSS ) - Software whose source code is willingly shared publicly so that other programmers can offer their own improvements.

proprietary software - Software that is only available in executable-code form. Only the owner(s) can access the source code.

protocol - See communication protocol.

proxy server - A piece of software that retrieves and delivers documents on demand. A proxy server programmed to filter ads from Web pages removes all ads before passing the pages to a browser.

pseudo-classes - CSS construct used to specify object properties when the object's state changes.

pseudo-element - One of two CSS constructs, first-lin e or first-letter .

public key - One half of a pair of PGP keys needed to decode an encrypted file.

public-key encryption (or double-key encryption or asymmetric encryption) - An encryption strategy based on a pair of code keys.

public-key infrastructure (PKI) - A system of public-key servers available to support encrypted communications over the Net.

query - A list of keywords given to a search engine.

raggy text - A block of text with variable line lengths ranging from very short to very long. Raggy text is hard to read and is almost always created unintentionally, usually with e-mail clients.

RAM - See random access memory.

random access memory (RAM) - A fast form of computer memory reserved for data used by the central processing unit (CPU) during a program execution; also called main memory or fast memory.

README file - A text file that accompanies a software download and contains information, usually late-breaking, that the user needs and that is not included in the software's official documentation.

read-only - Used to describe media that you cannot overwrite; compare with rewritable and writable.

ready-to-go executable - An entire computer program that can be stored in a single file and will not require a complicated installation process.

real-time - Refers to actions that must be performed immediately, or within a specified period of time.

relative link - See relative URL.

relative positioning - When a layer is placed on a Web page according to the order of its appearance in the HTML file.

relative URL (or relative link) - A hyperlink to a Web page on the same Web server.

relevance feedback - An information-retrieval technique used by some search engines that identifies reliably useful keywords on the basis of good representative documents.

reply-to-all - See group reply.

rewritable - Used to describe media that allow you to save bit patterns over and over again; compare with writable and read-only.

Rich Text Format (RTF) - An ASCII-based encoding system for storing rich-text documents (ones that include formatting information) such as Microsoft Word files that facilitates sharing with different applications.

robust network - A network that can continue to operate even if some parts of the network have been removed or simply fail to work.

rollover - An HTML effect that allows an interactive response to occur when the cursor moves over some HTML element.

root node - A unique node on a hierarchical network that is superior to all other nodes on that network.

rootkit - Software tools used to conceal running processes, files, or system data.

router - A computer that decides which path to use when sending data across the Internet.

routing (e-mail) - A way of directing mail to a specific folder or subdirectory for later viewing.

RSS client - Software client used to monitor and display published Web content.

RSS feed - Published Web content that can change dynamically.

RSS reader - See RSS client.

RSS server - A server that is used to publish dynamic Web content.

RTF - See rich text format.

scale - To resize an image on a Web page by increasing or decreasing its dimensions.

script - A small computer program written in a scripting language.

script kiddie - A hacker who is only superficially interested in computers and has little or no knowledge of programming.

scripting language - A computer language that is usually more limited and simpler than a full-edged programming language; it produces code that is relatively easy to read and extend.

search engine - An Internet application that returns a ranked list of documents from a large database of online documents in response to a search query. Most search engines for the Web are available for free on public Web servers.

Secure Sockets Layer (SSL) - A protocol used to establish secure (encrypted) communications between a Web browser and a Web server.

secure Web page/site - A Web server that uses encryption to prevent unauthorized people from reading transmitted messages is considered to be secure. Similarly, Web pages hosted by a secure server are considered secure.

selective-text indexing - A database indexing technique that is used for large text databases. Selective-text indexing accepts some subset of a document's text to be used as indexes for that document, while the rest of the text is ignored.

selector - A character code or string used to reference a specific HTML element or assign a label to a CSS rule.

self-extracting archive - A file archive that unpacks itself when you double-click it.

sender-only reply - An e-mail reply that is sent only to the original author of the current message; compare group reply.

server - An Internet host that serves information on the Net.

session key - A private key that is encoded with strong public-key encryption and sent to browsers by secure Web servers to enable encrypted SSL communications. Also used for PGP encryption.

shareware - Software that can be installed and evaluated for some fixed trial period at no charge but that requires a registration fee when the trial period ends.

shopping bots - Software programs that search the Web for the best deal on some product of interest.

sig file - See signature file .

signature file - A small text file that can be automatically appended to an e-mail message body. Sig files identify the sender in some way.

Simple Mail Transfer Protocol (SMTP) - The universal e-mail protocol for moving outgoing e-mail over the Internet.

single-key encryption - See private-key encryption .

site search - A search whose hits are restricted to Web pages within the current Web site.

site spoofing - Setting up a counterfeit Web site that looks identical to some other legitimate Web site.

Size attribute - An HTML attribute used to specify the size of a text input box or the number of options in a selection list.

smiley - The symbol :-), which tells the reader of an e-mail message when something is being said in jest; see also emoticons .

smish - The Instant Messaging version of phish.

SMTP - See Simple Mail Transfer Protocol.

social engineering - Misrepresentations and guises used by hackers to defeat computer security by tricking people to reveal sensitive information such as passwords.

social network - An online community where people with common interests can meet, share files, and find information.

software piracy - The unauthorized distribution of commercial software.

source code - A computer program written in some programming language.

spam - Unsolicited e-mail sent to a large number of recipients. Spam is usually commercial in nature, but it can be a plea for political action or a religious diatribe.

spam magnet - An e-mail account that attracts spam.

spambot - A computer program that automates the distribution of spam via e-mail or Usenet.

spear phishing - Phish sent to all members of some organization in the hopes of gaining access to the computer system for nefarious purposes.

specialized search engine - A search engine limited to Web pages that feature a specific topic.

spoofing - Using an electronic device to display a false phone number on a caller ID system.

spyware - Any software application that surreptitiously collects data about your computing activities and sends it to a data broker.

SSL - See Secure Sockets Layer.

standard colors - The 16 color names recognized by Web browsers: aqua, gray, navy, silver, black, green, olive, teal, blue, lime, purple, fuchsia, maroon, red, white, and yellow.

status bar - Information bar usually found at the bottom of the Web page.

storyboard - A handwritten mock-up of a Web page used for planning purposes.

streaming media - A strategy for playing very large media files in real time while the file is downloading over a bursty Net connection.

streaming technology - A Web transmission technology that allows a file to be viewed while being transmitted.

string concatenation - The process of joining strings together to make a single larger string.

string - A sequence of text characters that usually comprise a message or a word.

strong encryption - Encryption that cannot be cracked by brute force means within a reasonable period of time.

STYLE attribute - An HTML attribute used to specify display information for some Web page element.

STYLE element - An HTML element used to collect CSS style rules together in one place in an HTML file.

style sheet - A standalone text file containing CSS style rules that can be used by any HTML file.

subject tree - A hierarchically arranged collection of topic categories and Web page resources.

subscribe - The process of acquiring an RSS feed or joining a mailing list.

successive query refinement - A technique for working with search engines in which the user strives to formulate queries that are increasingly focused for the task at hand. Success depends on feedback from false hits along the way and on some familiarity with the features and options of the search engine.

tabbed browsing - When multiple pages can be displayed in a single browser window using tabs to switch from page to page.

tag, tagging - A descriptive word associated with an image, a bookmark, or some other Web content that forms an essential part of a folksonomy.

Tagged Image File Format (TIFF) - A file format for graphic images.

taxonomy - A formal method for organizing information.

TCP/IP - A combination of two protocols ( Transmission Control Protocol and Internet Protocol ) that mediate all communication over the Internet.

telnet - An Internet application that allows a user to log in to an account on a remote host and interact with that host as either a full-privileged user or a guest user.

terabyte (TB) - 1,024 gigabytes.

term count - The number of times a specific keyword or phrase occurs in a search engine's database.

terms of service (ToS - ) Restrictions that pertain to ISP accounts; similar to an acceptable use policy (AUP).

third-party cookie - A cookie created by some Web server other than the one that hosts the current Web page; compare to first-party cookie.

thread - An ongoing mailing-list discussion between two or more people on a particular topic.

threaded news reader - A news reader that collects all the replies to a given article and displays them in a group, thereby enabling the user to easily follow all the replies to an initial article.

throughput - See data rate.

thumbnail preview - A hyperlink to a graphical image whose label is a smaller version of that same image. Thumbnail previews are used to minimize download time and give the user more control over which images are viewed. Also known as a thumbnail sketch.

TIFF - See Tagged Image File Format.

tiling - Using a single background image to completely fill the Web page background, repeating the image as often as necessary to accomplish this.

TITLE attribute - Used to create a tooltip for an HTML element.

title bar - The bar across the top of the window that displays the Web page title.

TITLE element - In HTML, assigns a title to a Web page.

title search - A search-engine query containing a term that is tagged as a keyword or phrase that should be found in the title of the document. Not all search engines support title searches.

topic hierarchy - See directory and subject tree.

Top-Level Domain (TLD) name - The final suffix in a full domain name that reveals the type of the Internet host. For example, a top-level domain name will tell you if a host machine is part of a commercial ( .co m or .biz ) or educational site ( .edu ).

ToS - See terms of service.

traceroute report - A report that shows the precise pathway across the Net that a ping (or any other network transmission) will follow.

Transmission Control Protocol (TCP) - A communication protocol that prepares data for the trip from one Internet host to another. TCP works closely with Internet Protocol (IP) .

transparent GIF - A file whose background assumes the same background color or background pattern of any Web page on which it is displayed.

transparent PNG - See transparent GIF.

Trojan horse - Unauthorized code, often designed to enable remote control over a computer at a later date.

true color - Image color information that uses 24-bits or more.

TRUSTe privacy icon - Icon used as hyperlink to some Web site's privacy policy.

trusted key - A public key that you are certain cannot be a counterfeit key.

twisted-pair wiring - Copper wiring used in analog telephone lines.

unauthorized action - An intrusion associated with unauthorized access to and modification of pages on a Web server.

unauthorized disclosure - The practice of sending data from a browser to a Web server in the clear (i.e., unencrypted), thereby enabling hackers to intercept the transmission and obtain sensitive information.

Unicode - A new text encoding scheme that uses 16 bits.

uniform resource locator (URL) - A unique global address for Internet resources that are available through a Web browser, including files or directories on Web servers, FTP servers, telnet gateways, or news servers.

upload - To move a copy of a file on your local computer to a computer at a remote location. FTP clients are typically used to upload files over the Internet, although Netscape Navigator and Internet Explorer both support file uploads (see also download ).

Usenet - A client-server network of public message boards which predates the Web.

Usenet newsgroup - A discussion forum within the Usenet hierarchy in which anyone can ask questions or post messages.

user ID - A personal user identification.

user profile - A collection of data about a single user.

uuencode - An ASCII-encoding method used to move binary files across text-based communication channels (e.g., e-mail and Usenet).

variable - An object in some programming language used to store data to be processed.

viewer - An independent application that makes it possible to view a specific file format; examples include image viewers and PDF viewers.

virtual community - A group of people, usually brought together by some shared interest, who maintain ongoing group communications online.

virus - Potentially destructive code hidden in a host program and distributed to a large number of computers.

weak encryption - Encryption that can be cracked by brute-force means within a reasonable period of time.

Web - See World Wide Web (the Web).

Web 2.0 - The latest buzzword in the computer industry that usually refers to applications built using AJAX techniques.

Web browser - Client software used for viewing Web pages found on Web servers.

Web bug - A 1-pixel banner ad.

web of trust - A key-authentication model based on key certification by friends and friends of friends.

Web page - An online document you view with a Web browser.

Web server - A server that stores and manages Web pages for authors and users.

Web site construction kit - A program that helps you build Web pages or sites.

Web spider - A computer program used by search engines to locate new Web pages for their document databases

Web-based discussion group - See Web-based mailing list.

Web-based mailing list - A mailing list that has a Web-based interface.

Web-based software hosting - An arrangement in which proprietary software is made available to the public through the client-server model.

Webcast - A real-time multimedia broadcast transmitted over the Internet using streaming technology.

Weblog - See blog.

Web-safe colors - Colors that can be faithfully reproduced on any computer monitor regardless of the operating system used.

wiki - A Web site that allows members and/or visitors to add, modify, or remove content associated with a unifying theme.

Wikipedia - An online encyclopedia.

wildcard characters - Characters (such as *, #, and ?) used by some search engines inside keywords to broaden a query; wildcard matching retrieves morphological variations on a word and some variations on spellings.

Windows Rot - A phenomenon associated with Windows resulting in gradually degrading performance.

WinSCP - A Windows-based FTP client.

WinZip - A Windows-based file compression utility.

word size - The capacity of a central processing unit (CPU) for receiving, manipulating, and returning data during each processing cycle; sometimes called data width and measured in bits.

World Wide Web (the Web) - The collection of all documents available on the Inernet that use the HTTP protocol (Web pages).

worm - Potentially destructive code that depends on networked communications and commonly used software in order to propagate; similar to a virus.

writable - Used to describe media that allow you to save a bit pattern just once; compare with rewritable and read-only.

WYSIWYG editor - A Web page construction tool that allows you to modify a display version of your page rather than using the underlying HTML file. ( WYSIWYG stands for what you see is what you get.)

XML - eXtensible Markup Language standard used to create data-description languages, a standard way to encode data.

zipped file archive - A single file that can be unpacked (unzipped) to produce the multiple files it contains. Software files are often packed in a file archive for easy downloading.

zombie - A computer that is being controlled by a hacker using another computer without the owner's knowledge or permission, usually used to launch Internet attacks.