Cambridge IGCSE Computer Science (0984) Vocabulary Flashcards

Essential vocabulary terms and definitions for Cambridge IGCSE (9–1) Computer Science 0984 syllabus.

Denary

A base-$10$ number system.

Binary

A base-$2$ number system used by computers to represent all forms of data and instructions.

Hexadecimal

A base-$16$ number system used as a shorter representation of binary that is easier for humans to understand.

Overflow Error

An error that occurs during binary addition when a calculated value exceeds the storage capacity limit of a register, such as exceeding $255$ in an $8\text{-bit}$ register.

Two's Complement

A number system used to represent both positive and negative binary integers in an $8\text{-bit}$ register.

Sample Rate

The number of sound samples taken per second when converting an analogue sound wave to binary.

Sample Resolution

The number of bits allocated per sound sample.

Image Resolution

The total number of pixels that make up a digital image.

Colour Depth

The number of bits used to represent each colour in a digital image.

Lossy Compression

A compression method that reduces file size by permanently removing unnecessary data.

Lossless Compression

A compression method that reduces file size without any permanent loss of data.

Packet Header

The part of a data packet that contains routing metadata, specifically the destination address, packet number, and originator's address.

Packet Switching

A transmission process where data is broken down into packets, routed independently by routers across a network, and reordered upon reaching their destination.

Serial Transmission

A data transmission method where bits are sent one at a time sequentially down a single wire or channel.

Parallel Transmission

A data transmission method where multiple bits are sent simultaneously along multiple channels or wires.

Simplex Transmission

Data transmission that takes place in one direction only.

Half-Duplex Transmission

Data transmission that can take place in both directions, but not at the same time.

Full-Duplex Transmission

Data transmission that can take place in both directions simultaneously.

Automatic Repeat Query (ARQ)

An error detection protocol that uses positive/negative acknowledgements and timeouts to ensure data is received accurately by requesting retransmission when necessary.

Asymmetric Encryption

An encryption method that uses two mathematically related keys: a public key to encrypt data and a private key to decrypt data.

Microprocessor

An integrated circuit constructed on a single chip that carries out computer processing tasks.

Arithmetic Logic Unit (ALU)

The component of the CPU that performs arithmetic calculations and logical operations.

Control Unit (CU)

The CPU component that manages execution of instructions by decoding them and sending signals to control the flow of data within the system.

Program Counter (PC)

A register in the CPU that stores the memory address of the next instruction to be fetched.

Memory Address Register (MAR)

A CPU register that holds the memory address currently being accessed for reading or writing.

Memory Data Register (MDR)

A CPU register that holds the data or instruction fetched from RAM or waiting to be written to memory.

Current Instruction Register (CIR)

A CPU register that stores the instruction that is currently being decoded and executed.

Accumulator (ACC)

A temporary register in the CPU that holds the intermediate results of arithmetic and logic operations.

Instruction Set

The complete set of machine code commands that a specific CPU is designed to process and execute.

Embedded System

A computer system designed to perform a dedicated function within a larger electrical or mechanical device.

Primary Storage

Computer memory directly accessible by the CPU, consisting of RAM and ROM.

Secondary Storage

Non-volatile storage that is not directly accessed by the CPU, used for permanent storage of data and applications.

Virtual Memory

A technique using a designated section of secondary storage as temporary RAM when physical RAM space is exhausted.

MAC Address

A unique media access control address assigned to a network interface card at manufacture, written in hexadecimal using manufacturer and serial codes.

IP Address

A unique address allocated by a network to identify and locate a device, which can be static or dynamic.

Operating System

System software that manages files, handles interrupts, provides user interfaces, manages peripherals and memory, enables multitasking, and provides platform security.

Interrupt

A signal generated by hardware or software that temporarily pauses CPU processing so that an Interrupt Service Routine can handle the event.

Compiler

A translator that translates an entire high-level program into machine code executable files all at once and provides a complete error report.

Interpreter

A translator that translates and executes high-level code line-by-line, halting execution immediately when an error is encountered.

Uniform Resource Locator (URL)

A text-based web address that can include the protocol, domain name, and web page or file name.

Cookies

Small data files stored on a user's device by a web browser to hold login details, save personal settings, track preferences, or manage online shopping carts.

Blockchain

A digital ledger made up of a time-stamped series of unalterable records used to track digital currency transactions.

Expert System

An artificial intelligence system that simulates intelligent decision-making using a knowledge base, a rule base, an inference engine, and a user interface.

Machine Learning

A branch of artificial intelligence where a program automatically adapts its own processes and data.

Extreme Data

Test data values located at the absolute upper or lower boundary limits of acceptable input data.

Boundary Data

Test data consisting of the largest and smallest acceptable values along with their corresponding immediate rejected values.

Process Flowchart Symbol

A standard flowchart symbol representing an action or process being performed.

Subroutine Flowchart Symbol

A standard flowchart symbol representing a subroutine call linked to a separate flowchart.

Input/Output Flowchart Symbol

A standard flowchart symbol representing data being input or output.

Decision Flowchart Symbol

A standard flowchart symbol representing a decision point resulting in two alternative outcome paths.

Terminator Flowchart Symbol

A standard flowchart symbol representing the start or stop point of an algorithm process.