Computing KS4 Vocab
Key Vocabulary GCSE Computer Science OCR J277
Chapter 1 Systems Architecture
Hardware
Physical parts of the computer
Software
Programs that are used by a computer
CPU
Central Processing Unit; the main unit responsible for processing instructions
Memory
Hardware used to store data
GPU
Graphics Processing Unit; the main unit responsible for rendering and displaying images, animations and videos
Bus
A channel of communication used to transport data and instructions in the CPU
Register
A holding place to temporarily store data and instructions as they are being processed
Opcode
Part of an instruction that tells the CPU what operation to do
Operand
Part of an instruction that tells the CPU where to perform the operation
Chapter 2 Primary & Secondary Storage
RAM
The place in memory where all current programs and data in use are stored
Hard disk
A type of magnetic storage device inside a computer that is used to store data long-term
ROM
The place in memory where the ‘boot-up’ programs are stored
Operating system
The software that supports a computer’s basic functions
Paging
Separating data into sections called pages and switching the storage of them between RAM and virtual memory depending on how often they are used
Chapter 3 Data Storage & Compression
Analogue
The continuous stream of data that our senses process as humans
Digital
Data that is binary and represented as 1s and 0s
Binary
A base-2 number system that uses the values 0 and 1
ADC
A device that converts analogue data to digital data
Denary
A base-10 number system that uses the values 0 to 9
Hexadecimal
A base-16 number system that uses the characters 0 to 9 and A to F
Overflow
An error that occurs when the total from adding binary numbers cannot be stored within a byte of data
Character set
A list of characters used to create documents and their binary codes
Pixels
A small dot in an image; many of them together create an image
Metadata
Data that is stored with a file that provides information about how the file needs to be structured
Sampling
A sound measurement taken at a given point in a sound file
Sample rate
The frequency at which a sample in a sound file is taken
Lossy
A file compression method that permanently removes redundant data
Lossless
A file compression method that does not remove any data, but compresses data by looking for repeating patterns
Chapter 4 Computer Networks
Stand-alone computer
A computer that is not connected to a network
Network
A collection of computers that are connected together
Peripheral
A device that is attached to a computer system
Network traffic
The amount of data that is travelling across a network at any one time
Client
A computer that requests data and services from a server
Server
A computer that provides services and data for other computers on a network
Peer
A computer that is part of a network that is not controlled by a server
Data collision
The result of two devices on the same network attempting to transmit data at the same time down the same connection
Standard
Agreed-upon definition of a protocol, defining the rules of communication for network devices
Hardware
The physical parts of a computer system
Interference
Additional energy that appears in a network, that causes a signal to be disrupted
Bottleneck
Data that is delayed in transmission through an overloaded section of a network
Frequency
The rate per second at which vibration occurs, creating a wave
Encryption
Scrambling data to make it unreadable, to make transmitted data more secure
Internet
The largest WAN network
World Wide Web
The collection of web pages and protocols we access using the Internet
Protocol
A set of rules that govern network operations
Layer
An individual section of a protocol that is responsible for one part of the operation
Chapter 5 Network Security
Malware
Software that is designed to disrupt or harm a user’s computer
Social engineering
Targeting users of systems (rather than the systems themselves) to gain unauthorised access
Firewall
A security measure that prevents unauthorised traffic in or out of a network, using predetermined rules
Encryption
Scrambling data to make it unreadable, to add to security in transmitting the data. The receiver can then decrypt the scrambled data to reveal the actual data.
Chapter 6 Systems Software
Systems software
Controls the operation of hardware in a computer
Applications software
The everyday programs that we use to create documents and perform tasks
Hardware
The physical parts of a computer system
Device driver
A program that controls a particular device connected to a computer system
Utility software
Helps manage, maintain and control the computer’s resources
Operating system
Controls the operations of the hardware in a computer system and manages all other software
User interface
The way by which we interact with a computer system
Chapter 7 Ethical, Legal, Cultural & Environmental
Ethics
Moral principles created by society
Digital divide
The ever-growing gap between those who have access to computers and the Internet, and those who do not
Open source
Where the code for the software is made freely available and it can be freely modified
Source code
The list of programming commands that are compiled into an executable program
Proprietary
Software that is owned by a company or an individual that is not free to be modified
Compiled code
The executable code that is created from compiling the source code
Legislation
A collection of rules and laws, where people can be punished through sanctions
Sanction
A punishment, or action, for breaking a specific rule or law
Intellectual property
An individual or organisations’ property that is the result of their creativity
Chapter 8 Algorithms
Computational thinking
Breaking problems down in a logical way in order to find a solution
Algorithm
A sequence of instructions that solve a problem or perform a task
Flow chart
A diagrammatic way to represent an algorithm
Pseudocode
A way of designing a program in programming-type statements that are not specific to any programming language
Searching algorithm
The step-by-step procedure used to find an item of data in a data set
Sorting algorithm
The step-by-step procedure used to arrange a data set into an order
Trace table
A table that is used to trace a dry run of an algorithm
Chapter 9 Programming
Condition
A feature in an algorithm that can be met or not met, causing a different action to be taken
Loop
A sequence of instructions that is continually repeated a set number of times, or until a condition is met
Sequence
The order in which a set of instructions is carried out in an algorithm
Selection
A way of creating multiple paths and decisions in an algorithm
Variable
A named storage location that contains a value that can change during the execution of a program
Iteration
A way of repeating a set of instructions in an algorithm
Constant
A named storage location that contains a value that cannot be changed during the execution of a program
Array
A set of data that is stored together, that is of the same data type
Assignment
This is setting or resetting a value to a data location, such as a variable
Local variable
A variable that is declared within a function or procedure and can therefore only be used within that function or procedure
Global variable
A variable that is visible throughout the whole of the program
Procedure
A named section of instructions that perform a specific task
Dynamic array
An array that has does not have a fixed length applied to it when it is declared
Static array
An array that has a fixed length applied to it when it is declared
Concatenation
The joining together of characters in a string
Procedure
A named section of instructions that perform a specific
Function
A named section of instructions that perform a specific task and return a value from this
Syntax error
An error in the language written in a program
Logical error
An error in a program that causes it to produce unexpected results
Translator
Software that translates a program written in a programming language into machine code that can be understood by a computer
Database
A structured way of storing data
Validation
Techniques to check whether the input meets a set of criteria
Authentication
Techniques used to confirm a users’ identify
High-level language
A computer language, in which programs are written, that is closer to human language
Low-level language
A computer language, in which programs are written, that is closer to what a computer understands
Compiler
Software that translates a high-level language into machine code
Interpreter
Software that translates a high-level language by analysing and executing it line by line
Chapter 10 Computer Logic
Logic gate
The part of a digital circuit that controls the flow of electrical signals through the circuit
Voltage
The potential difference across an electrical component
Microprocessor
An integrated circuit that has similar functions to a central processing unit in a computer
Logic statement
A statement that is declared to be true or false
Truth table
A table that shows the breakdown of logic by listing every possible outcome
Logic circuit
Also known as a logic diagram, this is a combination of logic gates together to create a circuit
