COMPUTER CONCEPTS Vocabulary

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COMPUTER CONCEPTSVocabulary

• Chapter 4
• Computer Files and Data Storage

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File

• A named collection of data (such as a computer
  program, document, or graphic) that exists on a
  storage medium such as a hard disk, floppy disk,
  or CD-ROM.

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Information

• The words, numbers, and graphics used as the
  basis for human actions and decisions.

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File naming conventions

• A set of rules, established by the operating
  system, that must be followed to create a valid
  filename.

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Filename

• A unique set of letters and numbers that
  identifies a file.

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Filename extension

• A set of letters and/or numbers added to the end
  of a filename that helps to identify the file
  contents or file type.

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Wildcard character

• A symbol, such as an asterisk, used to represent
  a group of characters in a filename (for example,
  .exe means all files with an exe extension).

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Executable file

• A file, usually with an exe extension, containing
  instructions that tell a computer how to perform
  a specific task.

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Data file

• A file containing words, numbers, and/or pictures
  that the user can view, edit, save, send, and/or
  print.

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Generic filename extension

• A filename extension, such as bmp or txt, that
  indicates the type of data that a file contains,
  but does not indicate the specific program that
  was used to create the file.

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Application-specific filename extension

• A file- name extension that is associated with
  the files created using a specific software
  program, such as the doc extension associated
  with Microsoft Word files.

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Device letter

• The unique character by which each of the
  computer's storage devices can be identified. For
  example, the floppy disk drive is usually
  assigned device letter A.

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File manager utility software

• Software, such as Windows Explorer, that helps
  users locate, rename, move, copy, and delete
  files.

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Directory

• A list of files contained on a computer storage
  device.

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Folders

• The subdirectories (a subdivision of a directory)
  that can contain files or other folders.

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Root directory

• The main directory of a disk.

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File specification

• A combination of the drive letter, subdirectory,
  filename, and extension that identifies a file
  (for example, A\word\filename.doc). Also called
  a "path."

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Bit

• A bit is the smallest unit of information handled
  by a computer. A bit can hold one of two values,
  either a 0 or a 1. Eight bits comprise a byte
  which can represent a letter or number.

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Byte

• An eight-bit unit of information that represents
  a single character.

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Storage device

• A mechanical apparatus that records data to and
  retrieves data from a storage medium.

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Storage technology

• A term used to describe a storage device and the
  media it uses.

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Magnetic storage

• The recording of data onto disks or tape by
  magnetizing particles of an oxide- based surface
  coating.

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Read-write head

• The mechanism in a disk drive that magnetizes
  particles on the storage disk surface to write
  data, or senses the bits that are present to read
  data.

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Optical storage

• A means of recording data as light and dark spots
  on a CD, DVD, or other optical media.

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Cluster

• A group of sectors on a storage medium that, when
  accessed as a group, speed up data access.

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File allocation table (FAT)

• A special file that is used by the operating
  system to store the physical location of all the
  files on a storage medium, such as a hard disk or
  floppy disk.

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Sectors

• Subdivisions of the tracks on a storage medium
  that provide a storage area for data.

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Tracks

• A series of concentric or spiral storage areas
  created on a storage medium during the for-
  matting process.

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Defragmentation utility

• A software tool used to rearrange the files on a
  disk so that they are stored in continuous
  clusters.

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Fragmented

• When data in a file is stored in non- contiguous
  clusters.

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Undelete utility

• An operating system subcomponent, that, in some
  cases, allows the user to retrieve all or part of
  a deleted file.

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Access time

• The estimated time for a storage device to locate
  data on a disk, usually measured in milliseconds.
  

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Data transfer rate

• The amount of data that a storage device can move
  from a storage medium to computer memory in one
  second.

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Gigabyte (GB)

• Approximately one billion bytes exactly
  1,073,741,842 bytes.

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Kilobyte (KB)

• Approximately one thousand bytes exactly 1,024
  bytes.

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Megabyte (MB)

• Approximately one million bytes exactly
  1,048,576 bytes.

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Random access

• The ability of a storage device (such as a disk
  drive) to go directly to a specific storage
  location without having to search sequentially
  from a beginning location.

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Sequential access

• A form of data storage, usually on computer tape,
  that requires a device to read or write data one
  record after another starting at the beginning of
  the medium.

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Storage capacity

• The maximum amount of data that can be recorded
  on a storage medium, usually measured in
  kilobytes, megabytes, gigabytes, or terabytes.

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Terabyte

• Approximately one trillion bytes.

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Disk density

• The closeness of the particles on a disk surface.
  As density increases, the particles are packed
  more tightly together and are usually smaller.

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Double-sided (DS) disk

• A floppy disk that stores data on both the top
  and bottom sides of the disk.

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High-density (HO) disk

• A floppy disk that can store more data than a
  double-density disk.

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Zip disk

• A high-capacity floppy disk manufactured by
  lomega Corporation, frequently used for back-
  ups.

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Double-density (OD) disk

• A type of floppy disk with a higher storage
  capacity than single-density disks due to
  increased disk density.

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Cylinder

• A vertical stack of tracks on a hard disk. Hard
  disk One or more hard disk platters and their
  associated read-write heads (often used
  synonymously with hard disk drive).

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Hard disk platter

• The component of the hard disk drive on which
  data is stored a flat, rigid disk made of
  aluminum or glass and coated with a magnetic
  oxide.

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Disk cache

• Part of RAM used to temporarily hold information
  read from a disk, speeding up processing.

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Head crash

• A collision between the read-write head and the
  surface of the hard disk platter, resulting in
  damage to some of the data on the disk.

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RAID (Redundant Array of Independent Disks)

• Disks used by mainframes and microcomputers, in
  which many disk platters are used to provide data
  redundancy for faster data access and increased
  protection from media failure.

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Removable hard disks

• Hard disk cartridges that contain platters and
  read-write heads, and that can be inserted into
  and removed from the hard drive.

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Tape backup

• A copy of data from a computer's hard disk,
  stored on magnetic tape and used to restore lost
  data.

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Open reel tapes

• Large spools of computer tape that are sometimes
  used as a distribution medium for mainframe and
  minicomputer systems.

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Tape cartridge

• A removable magnetic tape module, similar to a
  cassette tape.

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CD-ROM

• A storage device that uses laser technology to
  read data from a CD-ROM.

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Read-only

• An indication that a computer can retrieve data
  from a storage medium such as a CD-ROM, but
  cannot write new data onto it.

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Archiving

• The process of moving infrequently- used data off
  a primary storage device to a storage medium such
  as a CD-ROM.

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CD-R

• An acronym for compact disc-recordable. CD-R is a
  type of optical disk technology that allows the
  user to create CD-ROMs and audio CDs.

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CD-RW

• An acronym for compact disc-rewritable. CD-RW is
  a type of optical disk technology that allows the
  user to write data onto a CD, then change that
  data much like on a floppy or hard disk.

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Multisession support

• Allows a CD device to write data during more than
  one session or read data that has been written on
  a CD during more than one session.

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Phase change technology

• A CD and DVD technology that uses disks with a
  modifiable crystal structure and allows users to
  add, modify, and delete data.

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DVDRW

• A DVD technology that allows users to record and
  change data on DVD disks.

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DVD-RAM

• A blend of technologies that allow users to
  record data on a DVD disk.

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DVD-ROM

• A DVD disk that contains data that has been
  permanently stamped on the disk surface.

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• Prepared by James Q. Jacobs