Glossary of Computing Terms

Glossary of Computing Terms

1. Computer System

   • A combination of hardware and software components that allow input, processing and outputs of data

2. Hardware

   • The physical components that make up a computer system

3. Software

   • The programs that run on a computer system

4. Input devices

   • Hardware devices that take real-word analogue data and convert it into a digital form that can be stored on a computer.
     • E.g, keyboard, mouse, microphone, webcam, scanner, sensors

5. Output devices

   • Hardware devices that use digital data from a computer to produce a form that is understandable to a person
     • E.g. monitors, printers, speakers, projectors

6. Reliability

   • How much you can depend on the computer system being available when you need it. usually measured in terms of availability

7. Availability

   • The proportion of time that a system is operational, usually expressed as a percentage over a certain period of time.
     • E.g. 95% measured over a year

8. MTBF

   • Mean Time Between Failure: a measure of availability often quoted by hardware manufacturers.

9. Redundancy

   • Spare hardware components are built into a system so, in the event of a component failing, the system can swap over to spare one.

10. Disaster recovery

    • Where a company has plans to replace a system quickly if there is a catastrophe (fire,flood,bomb etc.). Designed to minimise the time the system is down

11. Bit

    • A single binary digit: 1 or 0

12. Byte

    • 8 bits

13. Nibble

    • 4 bits

14. Kilobyte

    • 1024 bytes

15. megabyte

    • 1024 kilobyte

16. gigabyte

    • 1024 megabyte

17. terabyte

    • 1024 gigabyte

18. Binary

    • Base 2 number system, used by computer, uses the digits 1&0 only

19. Denary

    • base 10 number system, how we normally count, 0-9

20. Hexadecimal

    • Base 16 number system, to represent four bits

21. Overflow

    • when the result of a numeric calculation is too large to be stpred in the space reserved for that type of data

22. Character set

    • the set of symbols that can be represented by a computer. The symbols are called characters and can be letters, digits, space, punctuation marks and some control characters such as "eacape". Each character is represented by a numerical code that is stored as a binary integer

23. ASCII

    • American Standard Code for Information Interchange: a 7-bit character set used by PCs

24. EBCDIC

    • Extended Binary Coded Decimal Interchange Code: and 8-bit character set

25. Unicode

    • 16-bit character set that allows many more characters to be coded