Basic Computer Knowledge
Basic Computer Knowledge tests hardware, software, operating systems, office applications, internet use, networking and cyber safety at a practical level.
Core rules
- Input devices send data in; output devices present results. A keyboard and scanner are input; a monitor and printer are output.
- RAM is volatile working memory; ROM is non-volatile. The CPU contains the ALU and control unit.
- An operating system manages memory, processes, files, devices and users.
- Binary storage uses powers of 2: 1 KB = 1,024 bytes, 1 MB = 1,024 KB, 1 GB = 1,024 MB, 1 TB = 1,024 GB.
- HTTPS encrypts traffic between browser and server; it does not guarantee that a site is honest.
- Phishing, weak passwords, unpatched software and unsafe downloads are common security risks.
Worked example
How many megabytes are in 2 GB? Using binary units, 1 GB = 1,024 MB, so 2 GB = 2 × 1,024 = 2,048 MB. The reasoning is a two-step conversion, not 2 × 1,000 = 2,000 MB. If the question uses decimal storage units, it should say so; otherwise use 1,024.
Traps
- Mixing decimal (1,000) and binary (1,024) storage units.
- Calling RAM permanent storage; it loses data on power-off.
- Treating the World Wide Web as identical to the internet.
- Believing HTTPS makes a website trustworthy.
- Confusing file extensions: .docx is a document, .xlsx a spreadsheet, .pptx a presentation.
- Assuming deleting a file securely erases it from the drive.
Learn by matching each term to a device, function or risk, not by memorising isolated abbreviations.