Cameroon GCE A Level ICT key terms

Raw, unprocessed facts, numbers, symbols or observations that on their own carry little meaning. Processing turns data into information, so data is the input to any information system.

Data that has been processed, organised and given context so that it is meaningful and useful for decision-making. Its value depends on accuracy, timeliness, relevance and completeness.

The sequence of operations that converts raw data into useful output, typically input, validation, processing, storage and output. It may be done manually or by computer.

A combination of people, hardware, software, data and procedures that collects, stores, processes and distributes information to support an organisation's operations and decisions.

A computer-based system that turns operational data into regular summary reports used by managers to monitor performance and make tactical decisions, rather than day-to-day transaction handling.

A system that records and processes routine day-to-day business events such as sales, payments or stock movements, often immediately and with strong emphasis on accuracy and audit trails.

A method where data is collected over a period and processed together as one group at a scheduled time. It suits large volumes of non-urgent work such as payroll or end-of-month billing.

Processing in which input is handled immediately so that output is available fast enough to influence the event being controlled, as in air-traffic control, online booking or point-of-sale systems.

The physical components of a computer system, including the processor, memory, storage devices, input devices, output devices and the circuits that connect them.

The programs, instructions and associated data that tell hardware what to do. It is divided into system software, which manages the machine, and application software, which performs user tasks.

The part of the computer that fetches, decodes and executes instructions and controls other components. Its speed is affected by clock rate, word length and number of cores.

Volatile main memory that holds programs and data currently in use. Its contents are lost when power is removed, and larger capacity allows more programs to run at once.

Non-volatile memory whose contents are written during manufacture and normally cannot be changed. It stores firmware such as the bootstrap program needed to start the computer.

A small, very fast memory between the CPU and main memory that keeps frequently used instructions and data close to the processor, reducing the time spent waiting for slower RAM.

A technique where part of secondary storage is used as an extension of RAM, allowing programs larger than physical memory to run, though with slower access and possible disk thrashing.

A set of parallel conductors that carries data, addresses and control signals between the processor, memory and peripherals. Wider buses and higher clock speeds increase transfer rates.

System software that manages hardware resources, runs applications, controls memory and files, handles input and output, and provides a user interface and security functions.

A small system program that performs maintenance or housekeeping tasks such as virus scanning, disk defragmentation, backup, file compression or formatting, rather than running user applications.

Programs written to let users carry out particular tasks, such as word processing, spreadsheets, databases, graphics or browsing, as opposed to software that manages the computer itself.

Any hardware attached to and controlled by the computer, such as a keyboard, printer, scanner or external drive. Peripherals are classed as input, output or storage devices.

Hardware that sends data or commands into a computer, for example a keyboard, mouse, scanner, microphone, barcode reader or touch screen. Choice depends on accuracy, speed and data type.

Hardware that presents processed results to the user, such as a monitor, printer, plotter or speaker. Devices are chosen for speed, quality, volume and cost of the output required.

Non-volatile storage such as hard disks, solid-state drives, optical discs or flash memory that keeps data and programs permanently, unlike RAM which loses contents when switched off.

Storage media read or written by laser, such as CD, DVD and Blu-ray discs. They are cheap and portable but slower than hard disks, and rewritable versions allow reuse.

The process of getting data into a form a computer can process, often using methods such as barcode scanning, optical character recognition, magnetic ink or keyboard entry.

Automatic checking by software that entered data is reasonable and acceptable before processing, using rules such as range, type, length, format, presence and check-digit tests.

Checking that data has been copied or entered exactly as it appears in the source document, for example by double entry or visual comparison. It confirms accuracy rather than mere reasonableness.

An extra digit calculated from the other digits of a number and appended to it, so that later recalculation can detect typing or transcription errors in codes such as account numbers.

An organised collection of related data stored so that it can be accessed, managed and updated efficiently, usually under the control of database management software.

Software that creates, controls and secures a database, handling storage, queries, concurrent access, backup and recovery, and separating users from the physical details of the data.

A database organised as tables of rows and columns linked by shared key fields, which reduces duplication and lets data be combined through relationships rather than being repeated.

A field or combination of fields that uniquely identifies each record in a table, cannot be duplicated and is never left empty, so records can be reliably located and linked.

A field in one table that holds the primary key value of another table, creating a relationship between the two tables and enforcing referential integrity between their records.

A standard language for defining, querying and updating relational databases, using statements such as SELECT, INSERT, UPDATE and DELETE to work with tables of data.

Two or more computers and devices connected so they can exchange data and share resources such as printers, files and internet access, using agreed communication protocols.

A network covering a small area such as a room, building or campus, usually owned by one organisation and offering high speed and low cost of connection.

A network that spans a large geographical area, linking sites across cities or countries using leased lines, satellites or public services. The internet is the largest example.

The arrangement of devices and links in a network, such as star, bus, ring or mesh. The choice affects cost, reliability and how easily faults are found.

An agreed set of rules governing how data is formatted, sent, received and acknowledged between devices on a network, so that different systems can communicate correctly.

A unique numerical label assigned to a device on a network so data can be routed to it. IPv4 uses four octets; IPv6 uses much longer addresses to overcome shortages.