Overview of computing systems

What to revise

• two main constituents of a computer (hardware and software)
• characteristics of computers
• types, examples and uses of computer hardware
• logic circuits
• types, examples and uses of software

You should be able to

• define a computer system in relation to its nature and programmability and list its functional parts
• explain the characteristics of computers (electronic, accuracy, speed, interactive, reliability, consistency, large storage)
• identify the differences between hardware and software
• list components of computer hardware and their functions: CPU, peripherals (input and output devices), storage media
• explain the functions and examples of major input devices (keyboard, mouse, scanner, joystick, light pen, voice, digital camera) and the classification of keyboard keys
• define and give examples of output devices (monitor, printer, speaker, plotter) and compare inkjet, laser and line printers
• list the components of the CPU (ALU, control unit, registers) and explain their functions
• distinguish between primary and secondary memory; explain the uses and differences of RAM and ROM
• give examples of secondary storage (floppy disk, magnetic tape, hard disk, CD, DVD, USB) and compare them by size, speed, cost and technology
• list units of storage and their relationships (bit, nibble, byte, word, kilobyte, megabyte, gigabyte, terabyte)
• define register, bus and address; explain the functions of MDR, MAR, MBR, AC, PC and CIR
• explain the differences between register and main memory
• state the steps by which a computer converts data to information (input-process-output)
• enumerate factors affecting speed of data transfer (bus speed and bus width)
• define the types and uses of AND, NOT, OR, NOR and NAND gates
• interpret logic equations, list symbols and construct truth tables for AND, NOT and OR gates
• define comparator and construct a simple comparator with XOR and NOR gates
• differentiate between system and application software
• list types of system software (operating systems, utility software, middleware, device drivers, translators)
• define operating system, list its functions and user interfaces (command line, menu, GUI) and give examples (MS Windows, Linux, Unix; Android, Blackberry, iPhone)
• define utility software, list its functions, types and examples (editors, anti-virus)
• define translators and explain the differences among interpreter, assembler and compiler
• list examples of application software and their usage
• differentiate between open source and proprietary software
• describe methods of acquiring application software (built in-house and off-the-shelf)
• explain the differences between user application programs and general-purpose application packages
• give examples of off-the-shelf packages (word processing, spreadsheet, database, presentation, graphics, accounting, payroll, government, banking, statistics, educational, hospital)

From JAMB's Computer Science syllabus official. Full syllabus →

eZine's published bank has 30 questions on this topic (counted 29 October 2026).

Practice questions