The data in slack space, also known as latent data.
automated teller machine (ATM)
A machine that allows bank customers to perform certain transactions, such as withdrawing cash from their bank account. Also known as a cash machine or cashpoint.
A term that refers to the identification of people using biological characteristics such as fingerprints, iris recognition and DNA analysis.
A set of wires or optical fibres assembled, with a protective coating, for use as a communication medium.
An amount of memory on a disk drive that consists of a fixed number of sectors. Commonly a cluster contains 4 or 8 sectors. As a file is written to the disk, the file system allocates the appropriate whole number of clusters to store the file’s data.
see digital forensics
A legal protection that guarantees that the creators of content are rewarded for their work and protects the rights of users.
A set of computer-based data that has been organised so that it can be read, written, updated and searched. For example, a library catalogue.
defragment (or defrag)
(Also called defragmentation) An operating system process for optimising the physical location of files on a disk. As a disk is used, files are increasingly stored in fragments that can be scattered over the surface of the disk. Such fragmentation increases the length of time taken to read files. Defragmentation joins file fragments together so that a file is stored in continuous memory.
The process of applying a strong magnetic field to a magnetic storage device in order to erase any information held on that device.
(Also called forensic computing.) A branch of forensic science that is concerned with obtaining legal evidence from computer systems.
Digital rights management (DRM)
A range of technologies used by copyright owners to control how the content they produce is used.
Any technology that is based on representing data as sequences of numbers, i.e. as digital data.
Text characters or images that indicate someone’s mood by representing a simple facial expression. Text-based emoticons such as 🙂 are usually intended to be ‘read’ by tilting your head to one side. Also known as smileys.
A file system developed for Windows that is now mainly used by USB flash drives.
file allocation table (FAT)
A table in a FAT32 file system that holds information about where a file is stored on a hard disk or in an SSD.
The method by which an operating system controls how data is stored on and retrieved from the hardware.
A type of non-volatile memory of which its contents can be erased and rewritten.
The act of preparing a computer storage device for use by a file system. Any data previously held on the device is made unavailable to the operating system and the device appears empty.
An area on the internet designed for discussion, usually on a specific topic. Also known as a bulletin board system (BBS).
An unwanted process in HDDs where computer files are split across a number of physical locations on a disk as the disk becomes full. Fragmentation slows down file access.
global positioning system (GPS)
A set of satellites that continuously transmit their position so that anyone with a suitable receiver can obtain very accurate positioning information.
(Also called HDD and hard disk drive.) A data storage device used for storing and retrieving digital information using one or more rigid, rapidly rotating disks (platters) coated with magnetic material.
hard disk drive (HDD)
(Also called hard disk.) A data storage device used for storing and retrieving digital information using one or more rigid, rapidly rotating disks (platters) coated with magnetic material.
The physical components of a computer system. These include the large components such as the screen, the small component parts such as circuit boards, and all of the connecting cables.
A term used to describe the social and economic changes related to the development and widespread use of information technologies.
instant messaging (IM)
Text-based communication between people who are online at the same time.
The global internetwork that has grown from a US government-funded project started in the 1960s.
A society based on the acquisition, use and dissemination of information, made possible through advances in computing and IT; one where human knowledge is important for the economy.
(Also known as ambient data.)The data in slack space.
logical size (of a file)
The size of the content of a file. (Compare with physical size.)
Master File Table (MFT)
A table in a New Technology File System (NTFS) that holds information about where a file is stored on an HDD or SSD.
The part of a computer system that stores programs and data while they are waiting to be executed by a central processing unit.
A forum user who has responsibility for managing the forum and ‘moderating’ discussions to ensure that they follow the forum rules.
A set of guidelines for online behaviour.
A collection of devices that can communicate with each other. Networks vary in size and complexity, connecting anything from a few devices to many millions.
A term that is sometimes used interchangeably with ‘information society’, but which emphasises how the flow of information depends on networks.
New Technology File System (NTFS)
A file system commonly used in Windows computers.
online discussion group
A group of people, often with common interests or aims, communicating over the internet.
operating system (OS)
A collection of programs that manages a computer’s resources, provides an interface between the user and the computer, and organises the running of other programs. Examples include Windows, Mac OS and Linux.
overwriting (also called wiping or shredding)
The process of obscuring sensitive information that might remain on a disk before disposal. New data, usually just all zeros or all ones but sometimes a random pattern of both, is written to every part of the disk. This is a time-consuming process, especially if multiple overwrites are used.
The sections of a hard disk. When you format a hard disk, you can usually choose the number of partitions you want. Partitions are then seen as separate disks by the operating system.
physical size (of a file)
The size of the disk storage that is allocated to store a file, which will always be a whole number of clusters. (Compare with logical size.)
Using the work of other people to gain some form of benefit without formally acknowledging that the work came from someone else.
A step-by-step set of precise instructions for telling a computer how to carry out a particular task.
A term referring to any created content that is not subject to copyright. Material that is ‘in the public domain’ may be used freely by anyone.
A type of physical desktop card index for storing data, invented in the 1950s.
The smallest physical storage unit on a hard disk. In modern file systems it is almost always defined to be 512 bytes in size.
The unused space in a disk cluster. The difference between the physical size and the logical size of a file.
An electronic device that processes information and exchanges it with other devices.
The ‘short message system’ that allows text messages to be sent between mobile phones. SMS messages can also be sent between other devices, such as computers and landline phones.
The activities involved in building and maintaining online relationships and communities.
The programs that control the functioning of a computer system.
(Also called SSD.) A storage device that uses integrated circuit assemblies as memory to store data persistently. (Compare with hard disk drive.)
(Also called a solid-state drive.) A storage device that uses integrated circuit assemblies as memory to store data persistently. (Compare with hard disk drive.)
Control software that allows an operating system to inform a solid-state drive (SSD) which blocks of data are no longer considered in use and can be wiped internally.
A term describing something that seems to be everywhere at the same time.
The space on a hard drive that is available for the operating system to write to.
Malicious software that is designed to attack software on users’ computers, spreading quickly and easily from one computer to another.
A technique for prolonging the service life of some kinds of erasable computer storage media, such as flash memory, which is used in solid-state drives (SSDs) and USB flash drives. It does so by ensuing that, every time a file is modified, it is rewritten to a different physical location across the whole of the SSD, selected at random.
world wide web
An internet service that links computer files such as documents, images, audio and video. These files may be located on any computer connected to the internet. Also known as the web.