SSC CGL · Computer Knowledge
Abbreviations & History
Common computer acronyms, full forms and key inventors in computing history.
Eight concepts. Banking and SSC computer awareness asks for full forms and a few name–achievement pairs — CPU versus GPU, HTTP versus HTTPS, Babbage versus Berners-Lee — not arithmetic. Tables and pegs carry the load; nothing here earns a worked ledger.
- SSC CGL
- Easy level
- 6 concepts
- 40 practice questions
1Core hardware acronyms
Five expansions dominate hardware stems. CPU is the Central Processing Unit; GPU is the Graphics Processing Unit; RAM is Random Access Memory; ROM is Read Only Memory; ALU is the Arithmetic Logic Unit inside the CPU.
RAM and ROM are both memory, but they are not interchangeable: RAM is the working store that is typically lost when power goes; ROM holds firmware that remains after power-off.
Figure. CPU expands into ALU and CU; RAM and ROM name the two primary memories.
| Acronym | Full form | Role cue |
|---|---|---|
| CPU | Central Processing Unit | Main processor |
| GPU | Graphics Processing Unit | Graphics / parallel draw work |
| RAM | Random Access Memory | Volatile working memory |
| ROM | Read Only Memory | Non-volatile firmware store |
| ALU | Arithmetic Logic Unit | Does arithmetic and logic inside the CPU |
A technician says a machine's working programs vanish when the power cable is pulled, but the firmware that starts the machine is still there after power returns. Which pair of expansions matches those two stores?
- ROM = Random Access Memory (working); RAM = Read Only Memory (firmware)
- RAM = Random Access Memory (working, lost on power-off); ROM = Read Only Memory (firmware that remains)
- CPU = Central Processing Unit (working store); ALU = Read Only Memory (firmware)
RAM is the volatile working store; ROM holds firmware across power-off. Swapping the expansions is the usual trap. CPU and ALU are processing units, not those two memory classes.
2BIOS and OS
Two system expansions sit just above the raw hardware. BIOS is the Basic Input Output System — firmware that initialises hardware and hands off to the boot process. OS is Operating System — the software that manages hardware and runs applications after boot.
BIOS is not the operating system. Firmware that initialises hardware at power-on is BIOS; software that manages files and programs while you work is the OS.
Figure. BIOS/UEFI runs first at power-on and then loads the operating system.
| Acronym | Full form | When it matters |
|---|---|---|
| BIOS | Basic Input Output System | Power-on firmware / hardware init |
| OS | Operating System | Manages hardware and applications after boot |
Immediately after power-on, firmware must initialise the keyboard, disk controller and memory before any desktop appears. Later, a user opens files and runs apps under a named environment such as Windows or Linux. Which expansions match those two layers?
- OS = Basic Input Output System at power-on; BIOS = Operating System for apps
- BIOS = Basic Input Output System at power-on; OS = Operating System for managing apps
- ALU = Basic Input Output System; CPU = Operating System
BIOS is the power-on firmware; OS is the operating system that manages applications afterward. Swapping them is the trap. ALU and CPU are processing units, not these expansions.
3USB and HDMI interfaces
Two interface expansions appear constantly on ports and cables. USB is Universal Serial Bus — a general-purpose serial bus that works with many device types. HDMI is High-Definition Multimedia Interface — a digital audio/video link for displays and similar sinks.
Universal in USB means the bus is designed for many kinds of peripherals, not that it is wireless by definition.
Figure. USB carries data and power to peripherals; HDMI carries video and audio to a display.
| Acronym | Full form | Typical use |
|---|---|---|
| USB | Universal Serial Bus | Keyboards, drives, phones, many peripherals |
| HDMI | High-Definition Multimedia Interface | Monitor / TV audio-video link |
A laptop must charge a phone and also send picture-plus-sound to a conference-room display. Which pair of expansions matches those two cable jobs?
- HDMI = Universal Serial Bus for the phone; USB = High-Definition Multimedia Interface for the display
- USB = Universal Serial Bus for many peripherals including the phone; HDMI = High-Definition Multimedia Interface for the display
- HTTP = Universal Serial Bus; HTML = High-Definition Multimedia Interface
USB is the general peripheral bus; HDMI carries high-definition multimedia to a display. HTTP and HTML are web expansions, not cable interfaces.
4Web and hypertext acronyms
Web stems cluster around HyperText and resource naming. WWW is the World Wide Web. HTTP is HyperText Transfer Protocol; HTTPS is HTTP with Secure added via SSL/TLS encryption. HTML is HyperText Markup Language. URL is Uniform Resource Locator — the address string that locates a resource.
Anything starting with Hyper in this set relates to the web: HyperText in both HTML and HTTP.
Figure. WWW is the web of pages; a URL addresses one; HTTP transfers it; HTML marks it up.
| Acronym | Full form | Role cue |
|---|---|---|
| WWW | World Wide Web | The web itself |
| HTTP | HyperText Transfer Protocol | Transfers web pages |
| HTTPS | HTTP Secure (SSL/TLS) | Encrypted web transfer |
| HTML | HyperText Markup Language | Page markup language |
| URL | Uniform Resource Locator | Address of a resource |
A browser must fetch a page over an encrypted link, then render markup that includes hyperlinks. Which expansions name the secure transfer protocol and the markup language?
- HTML transfers the page; HTTPS is the markup language
- HTTPS is the secure transfer protocol; HTML is the HyperText markup language
- URL is the transfer protocol; WWW is the markup language
HTTPS is HTTP plus Secure (SSL/TLS). HTML is HyperText Markup Language. URL is an address; WWW names the web — neither is the markup language or the secure transfer protocol.
5IP, LAN, WAN and VPN
Four network expansions sit beside the web set. IP is Internet Protocol — the addressing and packet protocol of the Internet. LAN is Local Area Network; WAN is Wide Area Network. VPN is Virtual Private Network — a private path carried over a shared or public network.
LAN and WAN name coverage area, not speed. A VPN is not a fifth area class beside LAN and WAN; it is a privacy/tunneling arrangement that can ride on those networks.
Figure. LAN sits inside a wider WAN; IP addresses hosts; a VPN tunnels securely across the WAN.
| Acronym | Full form | Role cue |
|---|---|---|
| IP | Internet Protocol | Internet addressing / packets |
| LAN | Local Area Network | Building / campus scale |
| WAN | Wide Area Network | Long-distance / country scale |
| VPN | Virtual Private Network | Private path over a shared network |
A bank links teller PCs inside one branch building, links that branch to a distant city headquarters over long-haul links, and lets a home worker reach internal systems through an encrypted private path on the public Internet. Which expansions match those three arrangements in order?
- WAN, then LAN, then IP
- LAN, then WAN, then VPN
- VPN, then WAN, then LAN
One building is LAN; long-haul to another city is WAN; a private path over the public Internet is VPN. IP is the Internet Protocol, not an area class for the branch.
6PDF, GUI and ASCII
Three file and interface expansions appear outside the web stack. PDF is Portable Document Format. GUI is Graphical User Interface — windows, icons and pointers rather than a pure text command line. ASCII is American Standard Code for Information Interchange — a character encoding for letters, digits and common symbols.
ASCII is a character code, not a document format. PDF is a document format, not a character encoding.
Figure. PDF is a document format; GUI is the windowed interface; ASCII codes characters.
| Acronym | Full form | Role cue |
|---|---|---|
| Portable Document Format | Portable document file type | |
| GUI | Graphical User Interface | Windows / icons / pointer UI |
| ASCII | American Standard Code for Information Interchange | Character encoding |
A clerk saves a report so it looks the same on any reader's machine, then types letters that a program stores as standard character codes, while the desktop shows icons and a mouse pointer. Which expansions match those three ideas?
- ASCII = Portable Document Format; PDF = Graphical User Interface; GUI = American Standard Code for Information Interchange
- PDF = Portable Document Format; ASCII = American Standard Code for Information Interchange; GUI = Graphical User Interface
- GUI = Portable Document Format; ASCII = Graphical User Interface; PDF = American Standard Code for Information Interchange
PDF is the portable document format; ASCII encodes characters; GUI is the graphical interface. Swapping format and encoding is the usual trap.
Notes
- Core hardware acronyms: CPU = Central Processing Unit, RAM = Random Access Memory, ROM = Read Only Memory, ALU = Arithmetic Logic Unit.
- Web/network acronyms: HTTP = HyperText Transfer Protocol, URL = Uniform Resource Locator, HTML = HyperText Markup Language, IP = Internet Protocol.
- File/data acronyms: PDF = Portable Document Format, GUI = Graphical User Interface, ASCII = American Standard Code for Information Interchange.
- Pioneers: Charles Babbage = Father of the Computer; Tim Berners-Lee invented the WWW; Ada Lovelace is called the first programmer.
- Firsts: ENIAC was the first general-purpose electronic computer; the first computer mouse was invented by Douglas Engelbart.
Formulas
- CPU = Central Processing Unit; GPU = Graphics Processing Unit.
- USB = Universal Serial Bus; HDMI = High-Definition Multimedia Interface.
- WWW = World Wide Web; HTTP = HyperText Transfer Protocol; HTTPS adds Secure (SSL/TLS).
- BIOS = Basic Input Output System; OS = Operating System.
- LAN = Local Area Network; WAN = Wide Area Network; VPN = Virtual Private Network.
Exam traps & shortcuts
- Anything starting with 'Hyper' relates to the web: HyperText (HTML/HTTP).
- Babbage = 'Father of Computer', Lovelace = 'First Programmer', Berners-Lee = 'WWW' — fix these three name pairs.
- 'Universal' in USB stands for Universal (works with many devices) Serial Bus.
Reference tables
Full forms that recur across hardware, web, network and file stems. Expand from the acronym; do not invent rows beyond this sheet.
| Acronym | Full form |
|---|---|
| CPU / GPU | Central / Graphics Processing Unit |
| RAM / ROM | Random Access / Read Only Memory |
| ALU | Arithmetic Logic Unit |
| BIOS / OS | Basic Input Output System / Operating System |
| USB / HDMI | Universal Serial Bus / High-Definition Multimedia Interface |
| WWW / URL | World Wide Web / Uniform Resource Locator |
| HTTP / HTTPS | HyperText Transfer Protocol / HTTP Secure (SSL/TLS) |
| HTML | HyperText Markup Language |
| IP / LAN / WAN / VPN | Internet Protocol / Local / Wide Area Network / Virtual Private Network |
| PDF / GUI / ASCII | Portable Document Format / Graphical User Interface / American Standard Code for Information Interchange |
Keep these credits fixed; swapping Babbage and Berners-Lee is the classic trap.
| Name or machine | Credit |
|---|---|
| Charles Babbage | Father of the Computer |
| Ada Lovelace | First programmer |
| Tim Berners-Lee | Invented the WWW (1989) |
| ENIAC | First general-purpose electronic computer |
| Douglas Engelbart | First computer mouse |
Recap
If you keep only pegs, keep these.
- CPU / GPU
- Central Processing Unit; Graphics Processing Unit
- RAM / ROM
- Random Access (volatile working); Read Only (firmware remains)
- ALU
- Arithmetic Logic Unit — calculates inside the CPU
- BIOS / OS
- Basic Input Output System (firmware); Operating System (manages apps)
- USB / HDMI
- Universal Serial Bus; High-Definition Multimedia Interface
- HyperText
- HTML and HTTP both carry HyperText — web family
- HTTPS
- HTTP + Secure (SSL/TLS)
- URL
- Uniform Resource Locator
- LAN / WAN / VPN
- Local / Wide Area Network; Virtual Private Network (not an area class)
- PDF / GUI / ASCII
- Portable Document Format; Graphical User Interface; American Standard Code for Information Interchange
- Babbage / Lovelace / Berners-Lee
- Father of the Computer; first programmer; WWW (1989)
- ENIAC / mouse
- ENIAC = first general-purpose electronic computer; mouse = Douglas Engelbart
Practise Abbreviations & History
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