Today's digital devices use a variety of storage technologies. storage technologies such as hard disks, store data as particles oriented north or south. A hard disk drive provides multiple for data storage that are sealed inside the drive case to prevent airborne contaminants from interfering with the read-write heads. Hard disks are less durable than many other types of storage, so it is important to make a copy of the data they contain. storage technologies store data as a series of dark spots and light spots on the surface of CDs, DVDs, or BDs. Storage technologies, such as CD-,are often used for distributing software, but you cannot alter the disc's contents. technology allows you to write data on a CD, DVD, or BD, but you cannot delete or change that data. Rerecordable or technology allows you to write and erase data on a CD, DVD, or BD. state storage technologies, such as USB flash drives, store data by activating electrons in a microscopic grid of circuitry. A backup is a copy of one or more files that have been made in case the original files become damaged. A good backup plan allows you to restore a device's operating system, software, data files, settings, accounts, and profiles in case of a massive hardware failure or virus infection. Personal computer backups are typically recorded on hard drives, USB flash drives, network servers, and online storage services. An easy way to get a backup of important data files is to use the command to make duplicates and store them on a USB drive. Backup utilities such as File History and Time Machine use a technique called fileto make sure that files on two devices are the same. A disk is a bit-for-bit copy of the data from all sectors of a hard disk 5 7 5 9