A graphic image (and audio for vision impaired) recognition test to confirm a human, rather than a computer-automated response to a request. It is an acronym for Completely Automated Public Turing test to tell Computers and Humans Apart. It is commonly used with online forms over the internet to reduce the chance of hackers using computer programs to automatically fill in multiple bogus online forms.

an example of CAPTCHA

The environmental impact of an individual or organisation’s operation, measured in units of carbon dioxide. It includes primary emissions (the sum of the direct carbon dioxide emissions of fossil fuel burning and transportation such as cars and planes) and secondary, or indirect, emissions associated with the manufacture and breakdown of all products, services and food an individual or organisation consumes.

A set of instructions to describe the formatting (for example, layout, font, size) of a document written in a markup language such as HTML for web pages. It is a special case of a style sheet that is a set of instructions to define the formatting of a structured document (for example, a word processed document could have a style sheet). For example, CSS for a website may define the font, colour and size of each type of text such as headings, body text, hyperlinks and captions for pictures.

Data that are represented in discrete categories such as gender, eye colour or type of animal. For example, if age was represented as age groups (for example,. 0–5, 6–18, 19–60, 61+), then the data would be categorical rather than numerical.

A set of distinguishing aspects (including attributes and behaviours) of an object, material, living thing, system or event.

In Design and Technologies, the qualities of a material or object usually detected and recognised by human senses such as its colour, taste, texture, sound (for example, crunch of bread) and smell. The term also may relate to the form of a material, for example, ‘corrugated’ cardboard. These qualities are used by humans to select suitable materials for specific uses, for example, because they are appealing or suitable for their purpose. The characteristics of materials usually determine the way people work with the materials. Also see properties.

In Digital Technologies, for example, the characteristics of a stored digital graphic may be the colour depth (maximum number of colours represented), the resolution (number of pixels per area, or height and width) and the compression used.

Distributing computing over a network where storage of files, processing of data and/or access to software occurs automatically on interconnected server computers to which the user’s device is connected. Typically, people use the term to refer to accessing files and software over the internet. For example, photo files may be stored in the ‘cloud’ from a smartphone to be accessed later from a different location; where they are actually stored can be anywhere in the world on a server computer used by the cloudservice.

A piece of software that encodes or decodes digital audio-visual material, usually to allow it to be stored or transmitted in a compressed format. For example, the MP3 format compresses audio data and requires an MP3 codec (usually available by default in audio programs) to be read and played by a computer. Codecs can be downloaded or purchased and installed as plug-ins to most applications to extend the media capabilities of software. Also see compression.

A document that is created by more than one person, with authors working together to create a single document. This is readily achieved using digital technologies by having the document in an online environment so that many authors can access and edit the document at the same time.

Parts or elements that make up a system or whole object and perform specific functions. For example, the major components of a car include: a chassis (holds everything on it); an engine (to convert energy to make a car move); a transmission (including controlling the speed and output from the engine and to rotate the wheels); a steering system (to control the direction of movement); a brake system (to slow down or stop); a fuel delivery system (to supply fuel to the cylinders); an exhaust system (to get rid of gases) and an electrical system (for operating wipers, air conditioning, etc.).

Similarly, the components of a computer system may be a central processing unit (chips that follow instructions to control other components and move data); memory chips and a hard disk (for storing data and instructions); a keyboard, a mouse, a camera and a microphone (to input instructions and data for the central processing unit); a screen, a printer and speakers (to output data); USB and ethernet cards (to communicate with other systems or components). Also see digital systems.

diagram showing components of an electronic system

A process of encoding information using fewer bits, that is, 0 or 1, than an original representation, to reduce file size – typically using mathematical formulas to remove repeated data, combine related data or simplify data (for example, a line segment can be represented by the position of the end points instead of every dot on it). Common examples include:

  • .zip files, which can contain one or more files or folders that have been compressed
  • .jpg files in digital photography are produced by processing complete (lossless) data from a camera’s sensor through compressing (looking for redundant/unnecessary data) into a smaller file size
  • .mp3 files for audio, which compress an original audio source to reduce the file size significantly but still sound like an exact copy of the original.

a method of compressing data. Also see compression.

A problem-solving method that involves various techniques and strategies that can be implemented by digital systems. Techniques and strategies may include organising data logically, breaking down problems into parts, defining abstract concepts and designing and using algorithms, patterns and models.

Software used by designers, architects and engineers to create lines, shapes and planes that can be combined, moved, rotated, adjusted and rendered. Measurements and calculations can be included. Computer-aided drawing can be used to create two- and three-dimensional models and drawings such as floor plans, interior and garden designs, and to represent objects and structures. Also known as computer-assisted design or CAD.

A use of geometric design data (coordinates) to control and monitor specially designed automated machines with onboard computers to produce objects. Numerical control (NC) computer software applications create detailed instructions, known as G-code, that drive the computer numeric control (CNC) machine tools for manufacturing components and objects.

An environment developed, built and/or made by people for human and animal activity, including buildings, streets, gardens, bridges and parks. It includes naturalenvironments after they have been changed by people for a purpose.

A relationship between materials and suitable methods of joining them, based on their characteristics and properties. For example, certain adhesives can be used to join specific materials. If an incorrect adhesive is chosen, the materials will not bond, or will be weak.

A descriptive list of essential features against which success can be measured. The compilation of criteria involves literacy skills to select and use appropriate terminology.

A careful judgement in which opinions are given about positive and negative aspects of something. Critiquing considers good as well as bad performances, individual parts, relationships of individual parts and overall performance. Also see evaluating.

An advanced sensor to measure and record data about food or fibre crops and give real-time measurements of physiological factors such as nutrient status and moisture. It can be physically placed in the crop or remotely sensed from a satellite or aircraft.

Preparing and improving soil by digging and fertilising to promote the growth of crop plants.