Computing Grade 8 - Computer systems

Grade 8 Cambridge ICT

Software

A program or a set of instructions that tell a computer what to do to complete a task; aspects of a device you cannot touch.

Hardware

Physical parts of a computer that you can touch and see, e.g. the processor, storage devices, input devices, output devices.

Applications software

Software designed to do a particular task, e.g. a word processor, spreadsheet, web browser, mobile-phone app.

Systems Software

Software that helps a user run a computer

Operating system

Software that manages all the computer hardware and software; it also acts as an interface between computer hardware components and the user, and provides a platform where applications can run.

Device driver

Software program that operates a hardware device connected to a computer.

Security software

Any type of software that secures and protects a digital device. e.g. password locker, anti-virus, anti-spyware, firewall

Defragmentation

Reorganising files stored on a hard drive to ensure that all parts of the same file are located one after the other on the drive.

Analogue

Continually varying signal, e.g. a sound signal made from a violin.

Digital

A signal made of 1s or 0s, which allows it to be transferred electronically.

Digitise

Convert an analogue signal into digital format, i.e. into 1s and 0s.

Sampling

Taking samples of a sound wave at fixed intervals.

Binary digit

0 or 1; the smallest unit of binary data represented on a digital device.

Bit depth

The number of bits used to store a single sound sample.

Storage units

Number of bits used to store a data item in a digital device.

Character

A data type: a single letter, digit or symbol. e.g. 'x', '@'

Translator

Converts program instructions into machine-code format so the processor can carry out the instructions.

Compiler

Translates an entire computer program into machine code and creates a file containing machine code for the entire program.

Interpreter

Translates each line of high-level language code into machine code.

High-level language (HLL)

Programming language that uses commands and terms that are linked to the words or symbols a human would use when carrying out the same task.

Low-level language (LLL)

Programming language that uses commands that are similar to the type of instructions the processor understands.

Assembly language

Set of codes or symbols that represent each instruction, rather than a group of 1s and 0s.

Machine code

Combination of 1s and 0s that represent each instruction in the instruction set of a digital device.

Central Processing Unit (CPU)

The part of the computer that carries out program instructions, sometimes known simply as the processor.

Processor

Electronic circuitry that executes the instructions described in a computer program; often called the central processor or central processing unit.

Fetch

Collect an instruction from main memory.

Decode

Work out what an instruction means

Execute

Carry out the instructions described in a computer program.

Arithmetic logic unit (ALU)

The part of the CPU that carries out the calculations needed during the execution of a program.

Control unit (CU)

The part of the CPU that gives commands to other hardware components to ensure programs are carried out correctly.

Register

A special type of memory (it's very small, but very fast) in the CPU that is used to stores data the CPU uses when it's working. For example, information about memory locations and the instructions.

Random Access Memory (RAM)

Memory used to store programs and data currently being used by the CPU (the processor).

Main memory

aka Random Access Memory (RAM).

Logic circuit

Combination of logic gates for solving a problem in a digital device.

Truth table

Breakdown of a logic circuit, listing all possible operations the logic circuit can carry out.

Algorithm

Step-by-step instructions to solve a particular problem.

Conditional statement

Completes a check to see if sets a criteria if it is true or false, branching a pathway in a programTRUE or FALSE. e.g.
IF Name == "JC" THEN
OUTPUT "Hi JC"
ELSE
OUTPUT "Hi, who are you?"
END IF

Boolean expression

A statement that can be evaluated to True or False. Boolean expressions can contain conditional operators (e.g. >, < and =) and logical operators (e.g. AND, OR, NOT).

Artificial Intelligence

Software that can do human-like behavior, such as to learn and develop its own programming from the experiences it encounters.

Machine learning

The ability of a computer system to learn over time. Machine learning is a type of AI.

Industry 4.0

The use of new technologies in the manufacturing industry (factories that make things), making them more productive/faster and less wasteful. Examples of new technologies are machine learning, artificial intelligence, robotics.

Prototype

Initial product created for testing and reviewing, before a final product is released.

User experience

How intuitive and easy the product is to use.

Accessibility

How successfully a new product or piece of software can be used by anyone, including those with physical difficulties.

Ergonomics

How a product or piece of software is designed or arranged so that it can be used comfortably and efficiently.