Access Control List

A list of authorised users. If your name’s not down, you’re not getting in!


This is a user with access rights that allow them to manage the rights of other people, and carry out management tasks.

ADSL = Asymmetric Digital Subscriber Line

Internet connection over standard copper phone line.

Anonymous FTP = Anonymous File Transfer Protocol

This allows the public to log onto an FTP server by using a common login and any password, so that they can access files on the server. A benefit of this is that large files can be distributed, without needing to create several login details.


Anti-spam software prevents spam from entering a device by email. Anti-spam protocols are usually in place in email clients as standard, but you can purchase advanced anti-spam software to reduce the risk of malicious emails and cyber-attacks.


The way in which you identify yourself, and verify who you are. This is usually through a username and password, so that you can access restricted information on computers.

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Like a road for your data stream. A single-track lane would be a slow bandwidth, whilst a multi lane is like a motorway: wider and faster.


A binary digit (0 or 1), it’s the most basic unit of data that a computer can recognise and process.

BMP = Bitmap

Commonly found on Windows computers, a bitmap is an image format. You can easily identify this, as the file will usually have “.bmp” at the end of the name.


How you surf the web – Google Chrome, Microsoft Edge, Internet Explorer, etc…


A buffer contains data that’s stored for a short period of time, typically found in the computer’s memory (RAM).


A group of binary digits (0 and 1), that a computer processes in order to form a character (anything that you find on your keyboard). A byte consists of eight digits in total.

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Cable Broadband

Internet connection over coaxial cable.


A digital record of what you have done, either online or in a piece of software. This can be erased. There are several types of cache, including a browser cache (most web browsers cache website data by default), memory cache (for instance, data may be served in a system memory or RAM when an application is running), disk cache and processor cache.


Usually an image of distorted text, this is a challenge-response test that a user must pass, so that the computer can determine whether the user is a human or a bot.

Cloud Computing

A central storage point for your data that you can access from any device, anywhere via an internet connection.

CMS = Content Management System

A system that grants users multiple permission levels, in which they manage sections (or all of) the data, content or information found on a website.


Cookies are used to remember you and your website activity, including your preferences.

CRM = Customer Relationship Management

A system that helps organisations to manage their relationships with customers and potential customers. This includes aspects such as reporting, sales management and contact management, to ensure companies build and maintain relationships, whilst acting as productively as possible.

CSS = Cascading Style Sheet

A set of rules created by designers, that determine how web pages will look.

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Your filing system and data records held on your computer.


The process of restoring a file to its original style and format – the opposite of compressing a file.


Reserved for one user.

DHCP = Dynamic Host Configuration Protocol

This allows a server on a local network to assign a temporary IP address to a computer or other network device.

Dialog Box

Also referred to as a window, this is an enclosed area that a programme or process will display, to prompt a user to enter information into one or more boxes.

DNS = Domain Name System

The service that allows access to a networked computer by name, as opposed to IP address.


The name of a website, and part of an internet address. For example, our domain is air-it.co.uk.

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The way in which data is manipulated, so that only the person who is allowed to see the data can accurately interpret it.


Technology used in LAN (Local Area Network) to carry voice or data internally. Can also provide dedicated internet connection.


Connects telephone lines at the PSTN (Public Switched Telephone Network).


This refers to the suffix after the full stop at the end of the file name, and it displays the file type. For instance, .jpeg, .png, .csv.

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Fibre Broadband

Internet connection over fibere optic cable, typically faster than copper-based lines such as ADSL.


A filter for internal and external network traffic, a firewall can be created by using either hardware or software, and helps to keep your network secure.

Flash Drive

A small device that you can plug into your USB port. Functioning as a portable hard drive, you can access the files you’ve saved on your flash drive.

FTP = File Transfer Protocol

A way to exchange files over the internet to different computers.

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GIF = Graphics Interchange Format

An image file format that’s animated, by combining several other images into one file. They’re most popularly used on social media sites.

GDPR = General Data Protection Regulation

European regulation on how personal data is collected and stored by companies and organisations.

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The physical components of a computer – the monitor, disk drive, keyboard, internal chips and any wiring. Hardware is the counterpart to software.


A computer that’s accessed by a user who’s working in a remote location. Alternatively, it can also refer to a computer that’s connected to a TCP/IP network, like the internet.

Hosted (Telecoms)

Data and telephony services held remotely by the service provider.

HTTP = Hypertext Transfer Protocol

Data communication between your device and the world-wide web.

HTPS = Hypertext Transfer Protocol Secure

Encrypted data communication between your device and the world-wide web. Better and more secure to use when inputting personal or sensitive information.

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IaaS = Infrastructure as a Service

This is the most basic form of a cloud-service model, it’s essentially one of three “layers” in cloud computing (the other two being Platform as a Service (PaaS), and Software as a Service (SaaS)).

IoT = Internet of Things

An object capable of integrating into communication networks. e.g. A fridge that will text you when you run out of milk, heating and lighting systems you can control from your mobile, wearable fitness trackers and so on.

IP Address = Internet Protocol Address

Like a physical address, computers have one to connect to networks, including the internet.

ISP = Internet Service Provider

The company that provides your internet connection and services.

IVR = Interactive Voice Response

Allows the user to interact with phone systems via speech recognition or tones inputted by keypad. e.g. ‘For service desk please dial 3’.

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A scripting language that is used to add dynamic (interactive) content onto a website.

JPEG = Joint Photographic Experts Group

A graphic format that compresses an image in order to save space. JPEGs are usually found on websites in the form of detailed photographs or graphics.

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Kilobyte (K, KB, or Kb)

1,025 bytes (2 to the 10th power). It’s often used to represent 1,000 bytes.

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LAN = Local Area Network

Connects computers in a limited area. e.g. Your internal office network.

Log File

A file that lists all actions that have occurred.

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Mail Server

A networked computer that’s dedicated to supporting emails. Programmes such as Microsoft Outlook will retrieve new emails from the server, and will help you to compose and send messages.


Software programmes that have been designed specifically to cause damage or unwanted actions to a computer, such as viruses and trojan horses.

Mbit/s = Megabits Per Second

A unit of measurement referring to the speed data moves across the network. The faster the speed, the higher the number.

MFA = Multi Factor Authentication

An additional layer of security. You need both password and pin number to access the account. Without one or the other you cannot gain access.


Enables a computer to send and receive information over a telephone line. They can either be external or internal.

MPLS = Multiprotocol Label Switching

Transferring data more efficiently across high performance telecommunications networks.

MSP = Managed Service Provider

Manages information technology services for other companies – like us at Air-IT.

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A group of interconnected computers that are capable of exchanging information with each other.

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One-Time Password

Expires after single use.

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PAC = Port Authorization Code

Allows you to switch mobile service providers, whilst keeping your existing number.


Patch management is a process of updating and fixing flaws and vulnerabilities found in computer software. Patches can be applied to programs, applications and operating systems (OS).

PBX = Private Branch Exchange

A phone system within a company that switches calls between users on local lines, whilst enabling all users to share a certain number of external phone lines. This cuts the costs of each user having their own line.


A technique used to obtain sensitive information maliciously. Like fishing, the phisher will bait a line or cast a net to trap/catch unsuspecting prey. Usually this is in the form of an email, compelling the recipient to “open a document or attachment” which will land them in the “net”.


A software component that can be installed to add a specific feature to an existing computer programme.


A page description language that is usually used to print documents on laser printers.


A special kind of server that functions as a link between a web browser and a server. It intercepts requests for information from the server, and tries to fulfil the request if possible.

PSTN = Public Switched Telephone Network

Provides the infrastructure for the world’s public telephone network.

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A type of cyber-attack where your data is held hostage and the “kidnapper” demands a ransom to release it.

Remote Backup

A way in which users can backup and store their computer files.


The ability for a transportable wireless device (typically a mobile phone) to remain connected to the home network while overseas.


A piece of hardware that receives, analyses and moves incoming data from network to network.

RTF = Rich Text Format

A type of document that means special characteristics like margins and fonts can be included within an ASCII file.

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SaaS = Software as a Service

Another layer of cloud computing, usually accessed via a web browser. See IaaS.

Safe Mode

A way to start your Windows computer so that it can diagnose any problems. During safe mode, only basic files can be accessed.


A central computer that shares data and resources, providing functionality to other programs or devices.

SLA = Service Level Agreement

A contract between supplier and end user defining levels of service.

SIP = Session Initiated Protocol

Allows VoIP and video streaming over broadband connections.

SIP Trunking

Allows businesses to use VoIP instead of traditional telephony. Connects to the phone system over the internet.


A programme installed maliciously to record every move you make, and conversations you have online without your knowledge or consent.

SSL = Secure Socket Layer

This is an encryption system that secures internet communications.

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TIFF = Tag Image File Format

A popular file format that stores bit-mapped graphic images on a computer. The graphic can be any colour or resolution, and the name usually ends in “.tif”.  

Trojan Horse

A type of cyber-attack in the form of software that poses as an authentic application. Whilst it looks harmless, this is a programme that will perform harmful acts if you open and run it – so don’t open it!

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UC = Unified Communications

Integration of real time communications (all under one number) such as instant messaging, presence information (in/out of office), audio, voice, web and video.


Direct connection to the exchange, which is not shared with others.

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Virtual Hosting

A method for hosting multiple domain names on a computer, using just one IP address. This means one machine can share its resources such as memory and processor cycles.


A programme that’s designed to alter data on a computer, for destructive purposes. They’re usually transferred over the internet, but you can download anti-virus software to help protect your computer from them.

VoIP = Voice Over Internet Protocol

Allows users to make voice calls over the internet.

VPN = Virtual Private Network

A way in which you can securely access resources on a network by connecting to a remote access server, either over the internet or on another network.

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WAN = Wide Area Network

Connects computers in a wider geographical area by leased line or satellites. Typically contains two or more LANs.

WAP = Wireless Application Protocol

A set of communication protocols that enables wireless access to the internet.

WLAN = Wireless Local Area Network

The computers and devices that make up a network.

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XHTML = Extensible Hypertext Markup Language

A spinoff of hypertext markup language (HTML) that’s used to create web pages.

XML = Extensible Markup Language

A markup language for coding web documents, that allows designers to create their own customised tags to structure a page.

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This is a common file compression format. Zipped files usually end in “.zip”. Some zipped files are self-extracting, and end in “.exe”.

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