• A hard disk is an example of a nonvolatile computer storage device.hard disk in funzione image by Michele Campini from Fotolia.com
  
  Computers consist of different data storage devices that can be used for various types of programs and system applications. Some storage devices, such as CD-ROMs, are used to load software programs, while others, such as tape or disk media, are used to back up and restore system programs and applications. Computer users have discovered ways to use storage devices to manage system applications and programs.
  
  

Hard Disk

• Hard disk drives are nonvolatile digital storage devices that store various types of computer files. The hard drive consists of a boot sector that is read when the computer is turned on, which provides access to operating and software application programs on the disk. Hard disk drives can be installed as fixed disks in computers, servers and mainframes or as external disks connected to a system via USB or serial cable.
  
  

CD-ROM

• A CD-ROM disc is a media device that has multiple uses. Different types of data can be stored on a disc, such as documents, programs, video and music files. Formats related to various CD-ROM media, storage capacity and read and write capabilities are located in the industry standard "Rainbow Books." These books (red book, yellow book and orange book standards) explain the description of the layout, physics and coding of CD-ROM media.
  
  

Tape

• Tapes drives or media are also used to store and back up data. Tape drives are configured to use forms of media like reel-to-reel tape, cassette tapes and tape reels to store data. Tapes drives are mostly used for backing up system applications and programs. When a system has an error or a crash, tape reels are used to read each recorded transaction back into the computer system in a sequential manner. Mainframe computer configurations still use tape drives as a way of backing up their system applications.
  
  

USB Drive

• A USB flash drive is a faster, smaller, compact storage device with read/write capabilities similar to a hard disk drive. The device replaced the floppy disk drive as a favorite read/write storage device of computer users. Floppy disk drives had a capacity of 1.44MB, while USB drives can hold up to 3.0GB of information on a single drive. Most computers are manufactured with 2.0 USB ports that a flash drive uses to access system resources. USB flash drives can also store various types of files.