Common computer and IT abbreviations for clerk and operator tests, grouped by topic (hardware, memory, files, internet, software), with a one-line meaning for each.
Computer abbreviation questions are some of the quickest marks in any computer test, if you know them. The problem with long alphabetical lists is that unrelated terms sit next to each other, making them hard to remember. Grouping abbreviations by topic gives each one context.
Hardware and processing
| Abbreviation |
Stands for |
In one line |
| CPU |
Central Processing Unit |
The “brain” that executes instructions |
| ALU |
Arithmetic Logic Unit |
Part of the CPU that does calculations and comparisons |
| GPU |
Graphics Processing Unit |
Processes images and video |
| USB |
Universal Serial Bus |
Standard port for connecting devices |
| UPS |
Uninterruptible Power Supply |
Battery backup during power cuts |
Memory and storage
| Abbreviation |
Stands for |
In one line |
| RAM |
Random Access Memory |
Working memory; loses data without power |
| ROM |
Read Only Memory |
Stores firmware; keeps data without power |
| BIOS |
Basic Input/Output System |
Firmware that starts the computer |
| HDD |
Hard Disk Drive |
Storage on spinning magnetic platters |
| SSD |
Solid State Drive |
Fast flash storage with no moving parts |
| CD-ROM |
Compact Disc Read-Only Memory |
Optical disc, about 700 MB |
| DVD |
Digital Versatile Disc |
Optical disc, about 4.7 GB (single layer) |
| Abbreviation |
Stands for |
| LCD |
Liquid Crystal Display |
| LED |
Light Emitting Diode |
| OCR |
Optical Character Recognition (turns scanned text into editable text) |
| MICR |
Magnetic Ink Character Recognition (used to read bank cheques) |
| GUI |
Graphical User Interface (windows, icons, menus) |
| CLI |
Command Line Interface (typed commands) |
| Abbreviation |
Stands for |
| PDF |
Portable Document Format |
| JPEG |
Joint Photographic Experts Group |
| GIF |
Graphics Interchange Format |
| HTML |
HyperText Markup Language |
Internet and networking
| Abbreviation |
Stands for |
| WWW |
World Wide Web |
| URL |
Uniform Resource Locator |
| HTTP / HTTPS |
HyperText Transfer Protocol (Secure) |
| IP |
Internet Protocol |
| TCP |
Transmission Control Protocol |
| DNS |
Domain Name System |
| ISP |
Internet Service Provider |
| LAN / WAN / PAN |
Local / Wide / Personal Area Network |
| VPN |
Virtual Private Network |
| VoIP |
Voice over Internet Protocol |
| SMTP |
Simple Mail Transfer Protocol (sending email) |
| FTP |
File Transfer Protocol |
Software, data and emerging technology
| Abbreviation |
Stands for |
| OS |
Operating System |
| DBMS |
Database Management System |
| SQL |
Structured Query Language |
| AI |
Artificial Intelligence |
| IoT |
Internet of Things |
| GPS |
Global Positioning System |
| SIM |
Subscriber Identity Module |
How to learn them
- Learn one group per day, not the whole list at once.
- For each abbreviation, say the full form and the one-line meaning. The meaning makes the full form easier to recall.
- Test yourself with the left column only, then check.
When you are ready, practise with our Computer Abbreviations MCQs.