Computer Knowledge and Information Technology
Computer Knowledge and Information Technology is a scoring domain built on fundamentals rather than depth: hardware and software, operating systems, memory and storage units, number systems, word processing and spreadsheet operations, internet and email, networking basics, cyber security, and common abbreviations. Most items are one-line factual recalls, so revision of lists earns marks quickly.
Rules and facts to hold
- Memory ladder: bit, nibble (4 bits), byte (8 bits), kilobyte, megabyte, gigabyte, terabyte. In binary convention 1 KB = 1024 bytes.
- RAM is volatile and holds running programs; ROM is non-volatile and holds firmware. Cache is the fastest memory after registers.
- Computer generations: valves, transistors, integrated circuits, microprocessors, then artificial intelligence.
- Shortcuts: Ctrl+C copy, Ctrl+X cut, Ctrl+V paste, Ctrl+Z undo, Ctrl+Y redo, Ctrl+S save, Ctrl+P print, Ctrl+F find, F5 refresh, Alt+F4 close window.
- Extensions: .docx for Word, .xlsx for Excel, .pptx for PowerPoint, .pdf for portable documents.
- Networking: LAN is local, WAN spans large areas; IPv4 addresses are 32-bit, IPv6 are 128-bit; HTTPS is the encrypted form of HTTP.
- Security: phishing deceives users into revealing credentials, a firewall filters traffic, and a strong password is long and mixed.
Worked example
Convert the decimal number 25 to binary. Reasoning: subtract the largest powers of two - 25 = 16 + 8 + 1, with no 4 and no 2. Placing 1 in the 16, 8 and 1 columns and 0 in the 4 and 2 columns gives 11001. Verify by adding back: 16 + 8 + 1 = 25. Storage conversion follows the same care: 2 GB = 2 × 1024 MB = 2048 MB.
Traps
- MB (megabytes) versus Mb (megabits) in speed questions.
- Treating RAM as permanent storage.
- Calling Linux a programming language; it is an operating system kernel.
- Confusing a web browser with a search engine.
- Swapping undo (Ctrl+Z) with redo (Ctrl+Y).