Glossary of IT security terms - Protecting networks, computers and data

The technical terms in this glossary are not comprehensive, they are intended only as a basic aid to understanding the pages on this website. A much more comprehensive Jargon Buster can be found on the government’s Get Safe Online website.

Word/Term	Definition
Access control	Controlling who has access to a computer or online service and the information it stores.
Asset	Something of value to a person, business or organization.
Authentication	The process to verify that someone is who they claim to be when they try to access a computer or online service.
Backing up	To make a copy of data stored on a computer or server to lessen the potential impact of failure or loss.
Bring your own device (BYOD)	The authorised use of personally owned mobile devices such as smartphones or tablets in the workplace.
Broadband	High-speed data transmission system where the communications circuit is shared between multiple users.
Business continuity management	Preparing for and maintaining continued business operations following disruption or crisis.
Certification	Declaration that specified requirements have been met.
Certification body	An independent organization that provides certification services.
Chargeback	A payment card transaction where the supplier initially receives payment but the transaction is later rejected by the cardholder or the card issuing company. The supplier’s account is then debited with the disputed amount.
Cloud computing	Delivery of storage or computing services from remote servers online (ie via the internet).
Common text	A structure and series of requirements defined by the International Organization for Standardization, that are being incorporated in all management system International Standards as they are revised.
Data server	A computer or program that provides other computers with access to shared files over a network.
Declaration of conformity	Confirmation issued by the supplier of a product that specified requirements have been met.
DMZ	Segment of a network where servers accessed by less trusted users are isolated. The name is derived from the term “demilitarised zone”.
Encryption	The transformation of data to hide its information content.
Ethernet	Communications architecture for wired local area networks based uponIEEE 802.3 standards.
Firewall	Hardware or software designed to prevent unauthorised access to a computer or network from another computer or network.
Gap analysis	The comparison of actual performance against expected or required performance.
Hacker	Someone who violates computer security for malicious reasons, kudos or personal gain.
Hard disk	The permanent storage medium within a computer used to store programs and data.
Identification	The process of recognising a particular user of a computer or online service.
Infrastructure-as-a-service (IaaS)	Provision of computing infrastructure (such as server or storage capacity) as a remotely provided service accessed online (ie via the internet).
Inspection certificate	A declaration issued by an interested party that specified requirements have been met.
Instant messaging	Chat conversations between two or more people via typing on computers or portable devices.
Internet service provider (ISP)	Company that provides access to the internet and related services.
Intrusion detection system (IDS)	Program or device used to detect that an attacker is or has attempted unauthorised access to computer resources.
Intrusion prevention system (IPS)	Intrusion detection system that also blocks unauthorised access when detected.
‘Just in time’ manufacturing	Manufacturing to meet an immediate requirement, not in surplus or in advance of need.
Keyboard logger	A virus or physical device that logs keystrokes to secretly capture private information such as passwords or credit card details.
Leased circuit	Communications link between two locations used exclusively by one organization. In modern communications, dedicated bandwidth on a shared link reserved for that user.
Local area network (LAN)	Communications network linking multiple computers within a defined location such as an office building.
Macro virus	Malware (ie malicious software) that uses the macro capabilities of common applications such as spreadsheets and word processors to infect data.
Malware	Software intended to infiltrate and damage or disable computers. Shortened form of malicious software.
Management system	A set of processes used by an organisation to meet policies and objectives for that organisation.
Network firewall	Device that controls traffic to and from a network.
Outsourcing	Obtaining services by using someone else’s resources.
Passing off	Making false representation that goods or services are those of another business.
Password	A secret series of characters used to authenticate a person’s identity.
Personal firewall	Software running on a PC that controls network traffic to and from that computer.
Personal information	Personal data relating to an identifiable living individual.
Phishing	Method used by criminals to try to obtain financial or other confidential information (including user names and passwords) from internet users, usually by sending an email that looks as though it has been sent by a legitimate organization (often a bank). The email usually contains a link to a fake website that looks authentic.
Platform-as-a-service (PaaS)	The provision of remote infrastructure allowing the development and deployment of new software applications over the internet.
Portable device	A small, easily transportable computing device such as a smartphone, laptop or tablet computer.
Proxy server	Server that acts as an intermediary between users and others servers, validating user requests.
Restore	The recovery of data following computer failure or loss.
Risk	Something that could cause an organization not to meet one of its objectives.
Risk assessment	The process of identifying, analysing and evaluating risk.
Router	Device that directs messages within or between networks.
Screen scraper	A virus or physical device that logs information sent to a visual display to capture private or personal information.
Security control	Something that modifies or reduces one or more security risks.
Security information and event management (SIEM)	Process in which network information is aggregated, sorted and correlated to detect suspicious activities.
Security perimeter	A well-defined boundary within which security controls are enforced.
Server	Computer that provides data or services to other computers over a network.
Smartphone	A mobile phone built on a mobile computing platform that offers more advanced computing ability and connectivity than a standard mobile phone.
Software-as-a-service (SaaS)	The delivery of software applications remotely by a provider over the internet; perhaps through a web interface.
Spyware	Malware that passes information about a computer user’s activities to an external party.
Supply chain	A set of organisations with linked resources and processes involved in the production of a product.
Tablet	An ultra-portable, touch screen computer that shares much of the functionality and operating system of smartphones, but generally has greater computing power.
Threat	Something that could cause harm to a system or organization.
Threat actor	A person who performs a cyber attack or causes an accident.
Two-factor authentication	Obtaining evidence of identity by two independent means, such as knowing a password and successfully completing a smartcard transaction.
Username	The short name, usually meaningful in some way, associated with a particular computer user.
User account	The record of a user kept by a computer to control their access to files and programs.
Virtual private network (VPN)	Link(s) between computers or local area networks across different locations using a wide area network that cannot access or be accessed by other users of the wide area network.
Virus	Malware that is loaded onto a computer and then run without the user’s knowledge or knowledge of its full effects.
Vulnerability	A flaw or weakness that can be used to attack a system or organization.
Wide area network (WAN)	Communications network linking computers or local area networks across different locations.
Wi-Fi	Wireless local area network based uponIEEE 802.11standards.
Worm	Malware that replicates itself so it can spread to infiltrate other computers.

Glossary of cyber security terms