Computer Fundamentals
| Character encoding | Description |
|---|---|
| ASCII | 7/8-bit code for English characters, the earliest widely used standard |
| ISCII | Indian Script Code for Information Interchange — encodes Indian scripts |
| Unicode | Universal character encoding covering virtually all the world's scripts, now the dominant standard |
Hardware includes the CPU, memory, and peripherals; storage devices range from hard disks and SSDs to optical and cloud storage; input/output devices include keyboards, scanners, printers, and displays.
Types of Software and Programming Languages
| Software type | Examples |
|---|---|
| System software | Operating systems, device drivers, utilities |
| Application software | Library management systems, office suites, browsers |
Programming languages are classed as Object Oriented (Java, Python, C++), Procedural (C, BASIC), High Level (readable, close to human language), Scripting (JavaScript, PHP, Python for automation/glue code), and Web languages (HTML, CSS, JavaScript for building web pages).
Telecommunication and Wireless Communication
Transmission channels/media include copper wire, coaxial cable, and fibre optics; transmission mode can be simplex, half-duplex, or full-duplex. ISDN and PSDN are early digital/packet-switched network standards; multiplexing combines multiple signals over one channel; modulation encodes data onto a carrier wave.
Wireless communication spans Wi-Fi (radio-based local wireless networking), Li-Fi (data transmission via visible light), satellite communication, and mobile/cellular communication (2G through 5G generations).
Computer Networks
| Topology | Description |
|---|---|
| Bus | All devices share a single communication line |
| Star | All devices connect to a central hub/switch |
| Ring | Devices connect in a closed loop |
| Mesh | Devices interconnect with multiple redundant paths |
Network types by scale: LAN (Local Area Network, confined to one building/campus), MAN (Metropolitan Area Network, city-wide), WAN (Wide Area Network, spans countries/continents — the internet is the largest WAN).
Internet Basics and Search Engines
The World Wide Web (WWW) is a system of interlinked hypertext documents accessed via the internet using web browsers. E-mail enables asynchronous messaging. Search engines (Google, Bing) index web content and rank results by relevance; meta search engines (e.g., Dogpile) query multiple search engines simultaneously; entity search engines return structured facts about a specific entity rather than a list of links.
Internet Protocols and Standards
| Protocol | Function |
|---|---|
| HTTP / S-HTTP | Transferring hypertext (web page) content, with S-HTTP adding a security layer |
| FTP | Transferring files between computers over a network |
| SMTP | Sending e-mail messages between servers |
| TCP/IP | The foundational suite of protocols governing how data is packaged, addressed, and routed across the internet |
| URI / URL | Uniform Resource Identifier (general identifier)/Locator (identifier that also specifies how/where to access the resource) |
Hypertext, Hypermedia, Multimedia and Immersive Technologies
- Hypertext — text containing links to other text, enabling non-linear navigation.
- Hypermedia — hypertext extended to include linked images, audio, and video.
- Multimedia — content combining multiple media types (text, audio, video, animation).
- Video conferencing — real-time audio-visual communication across locations.
- Virtual Reality (VR) — a fully immersive, simulated digital environment.
- Augmented Reality (AR) — overlays digital elements onto the real-world view.
Data and Network Security
- Firewalls — filter incoming/outgoing network traffic based on security rules.
- Cryptographic techniques — encrypt data so only authorised parties can read it (symmetric and asymmetric/public-key encryption).
- Anti-virus and Anti-spyware software — detect and remove malicious programs.
- Intrusion Detection System (IDS) — monitors network/system activity for suspicious behaviour and policy violations.