means it is executable $($can run as a program$).$ Is the "prezip" a program? @ after a file means it is a symbolic link.

Does $"$K$01$ssh$"$ have a symbolic link?

$13.$ There are dot files $($aka hidden files$)$ in your home directory. Look at them by typing in k $-$a and pressing Enter. A dot file, also called a "hidden file," starts with a dot $($period$)$ and is not displayed unless the $-$a option is used with the ls command.

How many hidden files are in your home directory?

$14.$ Navigate to your home directory, now just type in Is and press Enter. You should not see the dot $($hidden$)$ files in this listing. This happens because you need to use the $-$a option on the Is command to see them.

$15.$ Now try a long listing, by typing in $l-l$ and pressing Enter. The $-$I option is a lowercase $L$ and not a number one. Don't worry about all the information shown; you will be learning about this information in later chapters.

$16.$ Look at the items at the root $(/)$ filesystem by typing $k\frac{?}{?}$ and pressing Enter. Can you tell whether ${?}_{(})$ these are directories or not? $($It$\text{'}$s okay if you can't tell. You'll be able to tell in the next step.$)$

$17.$ Add an indicator to the end listed item by typing $k_{-}\frac{F}{{?}_{?}}$ and pressing Enter. Remember that the forward slash $(/)$ indicator tells you that the item is a directory, whereas a blank indicates the item is a file. How many directories are there?

$18.$ Now you will try something different and attempt to change your present working directory to various places across the filesystem using relative and absolute directory references. First navigate to the $/$bin directory by typing

cd $/$etc and press Enter.

Entering a directory or file reference starting with a forward slash $(/)$ is called using an "Absolute Directory Reference."

$19.$ Now see where your present working directory is currently located by typing in pwd and pressing Enter. This indicates your present working directory is now at the $/$etc directory.

Are you in the $/$etc directory?

$20.$ Use another absolute directory reference to take you back to the user account's home directory by typing cd directory and pressing Enter, where directory is your account's home directory, which you recorded in step #$3.$

Remember that an absolute directory reference ABSOLUTELY starts with a forward slash $(/).$