CIS 105 Survey of Computer Information Systems

1. CIS 105Survey of Computer Information Systems Essential Concepts and Terminology Study Unit Three

2. 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.

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

4. Folders. • PC. The subdirectories that can contain files or other folders. • Macintosh. Same as directories on a PC.

5. Memory. • The computer circuitry that holds data waiting to be processed.

6. Storage. • The area in a computer where data is retained to be used again later. Storage devices retain information after the device is turned off.

7. Volatile Memory. • Memory contents that are erased when a computer is shut off.

8. Saving. • Transfer of data to a storage device.

9. Read-Write Media. • Storage disks that allow a computer to both read and store (write) data. Examples are CD-RW and floppy disks.

10. Sequential Access. • A form of data storage (such as a computer tape) that requires a device to read or write data one record after another starting at the beginning of the medium.

11. Random-Access. • The ability of a storage device to go directly to a specific location rather than searching sequentially from a beginning location. Magnetic disks are random-access storage media.

12. Pits. • Microscopic indentations on optical storage media used by laser beams to read patterns of data on the surface of disks. The light-sensing reading device receives no light from a pit and returns a "0" signal.

13. Land. • Flat, reflective areas on optical storage media the bounces laser light, returning a "1" signal.

14. Online Storage. • Immediately available storage which does not require a user action, such as inserting media. Typically, a hard disk is a personal computer's online storage device.

15. Near-Online Storage. • Secondary storage that requires insertion of media. Storage readily made available by user action.

16. Access Time. • The estimated time for a storage device to begin reading data on a disk, usually measured in milliseconds for disks and nanoseconds for RAM.

17. Nanosecond. • One-billionth of a second.

18. Solid State Disk. • A high-capacity storage device with rapid access time, comparable to hard disks. The device stores up to 8 GBs of data and uses batteries to provide data involatility.

19. Double-Density (DD) Floppy Disk. • A type of disk with a higher storage capacity (800 K) due to increased disk density.

20. High-Density (HD) Floppy Disk. • A disk that stores more data than a double-density disk, up to 1.44 MB.

21. Write-Protect Tab. • A sliding notch on floppy disks that, when open, protect disks from being overwritten or deleted.

22. Tracks. • Concentric or spiral storage areas created in series during formatting on storage medium.

23. Sectors. • Pie-shaped subdivisions of tracks on storage media.

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

25. File Allocation Table (FAT). • A table of information recording the physical location of files on storage medium.

26. Fragmentation. • Storage of a data file in non-contiguous clusters.

27. Activity Light. • An indicator that illuminates while the head is reading or writing data on a disk, indicating not to press the eject button.

28. Formatting. • The process of preparing a magnetic disk to store information. The process of a disk drive's head laying down the magnetic pattern of tracks and sectors.

29. Hard Disk. • One or more magnetic disk platters providing high-capacity, high-speed online storage.

30. Platters. • Fixed, rapidly-rotating magnetic storage component disks of a hard disk.

31. Head Crash. • A collision between the read-write head and the surface of a hard disk platter, resulting in disk damage.

32. Partition. • A section of a disk established to operate as if it were a separate disk.

33. Positioning Performance. • The speed at which a drive can position the read/write head to begin transferring data.

34. Transfer Performance. • The speed at which a drive can transfer data.

35. Spindle Speed. • The number of revolutions per second at which hard disk platters rotate.

36. Hard Disk Controller. • A circuit board on the mother board, on an expansion card, or in a hard drive that acts as an interface between the CPU and the hard disk.

37. Small Computer System Interface (SCSI). • An interface standard used for attaching peripheral devices such as drives, scanners, and other peripherals. Pronounced "scuzzy."

38. Disk Cache. • A type of RAM used to temporarily store information read from a disk, dramatically improving up hard disk performance.

39. Archiving. • The process of moving data off a primary storage device to a long-term storage medium such as a CD-ROM or removable magnetic medium.

40. Backup. • A duplicate copy of data.

41. CD-ROM. • A read-only, optical disk storage medium that uses laser technology to read data.  An acronym for compact disc read-only memory.

42. CD-ROM drive. • A device that uses laser technology to read data from a CD-ROM. CD-ROM drive speed is stated in multiples of 150,000 bits per second, such as 2x or 4x.

43. Multisession CDs. • A CD that allows a device to write (burn) data during more than one session.

44. CD-R. • An optical disk technology used to create CD-ROMs and audio CDs. An acronym for compact disc-recordable.

45. CD-RW.   • An optical disk technology that allows data to be written onto a CD, then changed much like on a floppy or hard disk.  An acronym for compact disc-rewritable.

46. DVD. • An optical storage medium similar to CD-ROM, except with higher storage capacity (up to 17 GB). The acronym for "digital video disc" or "digital versatile disc.” DVD-ROM drives are downwardly compatible with CD-ROM.

47. PC Card (PCMCIA Card). • A credit-card-sized circuit board, typically used to connect a modem, memory, network card, or storage devices to a notebook computer.

48. End of Study Unit 3. Return to first slide Move to Study Unit 4 CIS 105 Home Page Created by James Q. Jacobs