Amplifier An electronic circuit that increases the strength of an electric signal. For example, an amplifier can convert the weak signal from a radio tuner into a signal strong enough to power a speaker.

Analogue Whereas digital systems use only two values, 1 or 0, to store data, analogue, or non-digital systems, use an infinite range of values. In an analogue circuit, current can be of any strength, while in a digital circuit, current can only be on or off.

Binary A number system that uses only the digits 0 and 1. This can be represented in digital circuits by turning currents on (1) or off (0). A binary “word” uses multiple binary digits to represent decimal numbers. Almost any information can be represented in binary.

Bit The basic unit of information in digital electronics. A “bit”, short for “binary digit”, is represented either by 1 or 0.

Byte A sequence of eight bits, the number needed to represent a number or letter on a computer. Bytes are often used to measure the size of a computer’s memory.

Capacitor An electronic component that stores electric charge. It consists of an insulator between two conducting plates.

Circuit board An insulating board on to which electronic components are soldered (connected by metal). Metal tracks connect the components to form a circuit.

Digital Information that is stored as binary numbers only. In a digital circuit current can only have two strengths—on and off.

Digital picture An image on a computer, made up of pixels in a grid pattern. Each pixel has a position, colour and brightness, stored as binary on the computer.

Digitization The process of turning analogue information into digital form. Analogue information must be turned into digital form before it can be handled by digital circuits.

Diode A semiconductor device that allows an electric current to flow through it in one direction but not the other.

Electric conductor A material that allows electrons to flow through it freely. Most metals are good electric conductors.

Electric insulator A material that reduces or stops the flow of electricity. Plastics and rubber are good electric insulators.

Electrode An electric conductor that leads electricity to or from the non-metallic parts of a circuit, such as plastic in a capacitor.

Electronic circuit An electric circuit made up of electronic components. By combining different components in different ways, it is possible to make electronic circuits which can do almost any job.

Electronic component A basic part of an electronic circuit, such as a resistor or diode. Components control the flow of electric current in order to carry out tasks.

Electronic signal A signal made by continuously changing the strength and direction of an electric current. Digital signals use pulses of electricity to represent binary numbers.

Electronics The study of how electrons behave and how they can be made to do useful jobs. Electrons are tiny particles inside atoms, the building blocks of matter. In some materials, such as metals, they can move easily from one atom to another. If electrons are made to flow along a pathway, such as a wire, an electric current is produced. By controlling electric currents, an electronic device can carry out a wide range of tasks.

Integrated circuit An electronic circuit made of microscopic components built into a small piece of silicon. Components are built in using chemical and photographic processes. Integrated circuits are often called silicon chips or microchips.

Light-emitting diode (LED) A diode that makes light when an electric current flows through it.

Pixel A tiny coloured dot, which is the smallest part of a digital image. Pixel is short for “picture element”.

Resistor An electronic component that restricts the flow of current in a circuit.

Resolution The concentration of pixels in a picture. High-resolution, or “hi-res”, graphics, made up of millions of pixels, can be viewed on a large screen without individual pixels becoming visible.

Semiconductor A substance that can act either as an electric conductor or as an insulator.

Silicon A non-metallic element found in many rocks. It can be extracted from the rocks, purified and treated to make a semiconductor. Silicon is widely used as a semiconductor in integrated circuits.

Switch An electronic component that can be used to break the flow of electrons around an electronic circuit.

Transistor A semiconductor device that can act as a switch or an amplifier. The current flowing between two connections is controlled by a current flowing into a third.

Consultant: Chris Oxlade