IT jargon buster

An A–Z of common IT terms

Antivirus

Software that detects and removes malicious programs from your devices.

Backup

A separate copy of your data, kept safe so you can recover it if your device is lost, broken or attacked.

Bandwidth

How much data your internet connection can carry at once — more bandwidth means faster, smoother use.

The cloud

Storing files and running software over the internet instead of only on your own computer, so you can reach them anywhere.

Cyber Essentials

A UK government-backed certification showing a business has the essential security controls in place.

Data breach

When personal or business information is stolen or exposed from a company’s systems.

DNS

The internet’s address book — it turns website names like 365techies.co.uk into the numbers computers use to connect.

Encryption

Scrambling data so only someone with the key can read it — protecting information if a device is lost or intercepted.

Endpoint

Any device that connects to your network — a laptop, PC, phone or tablet.

Firewall

A barrier that controls what’s allowed in and out of your network, blocking unwanted traffic.

Hardware

The physical parts of your tech — the computer, screen, router, printer and so on.

IP address

A unique number that identifies a device on a network or the internet.

Malware

A catch-all term for harmful software — viruses, spyware, ransomware — that can damage devices or steal data.

MFA (Multi-Factor Authentication)

An extra login step, like a code on your phone, so a stolen password alone isn’t enough to get in.

Microsoft 365

Microsoft’s subscription bundle of Outlook, Word, Excel, Teams and online storage, for home and business.

MSP (Managed Service Provider)

A company that proactively manages your IT for a monthly fee — like an outsourced IT department.

NAS (Network Attached Storage)

A shared storage box on your network that everyone can save to and back up to.

Operating system

The core software that runs a device, such as Windows or Android.

Patch / update

A fix from a software maker that improves security or sorts out bugs — keeping up to date is vital.

Phishing

Fake emails or messages designed to trick you into giving away passwords, money or personal details.

Ransomware

Malicious software that locks up your files and demands payment to release them. Good backups are the best defence.

Remote support

When we securely connect to your device over the internet to fix a problem, while you watch on screen.

Router

The box that connects your home or office to the internet and shares it over Wi-Fi and cables.

SaaS (Software as a Service)

Software you subscribe to and use online, rather than installing it once.

Server

A powerful central computer that stores files or runs services for other devices on a network.

SLA (Service Level Agreement)

A written promise of the service levels you can expect, such as response times.

Smishing

Phishing carried out by text message.

Software

The programs and apps that run on your devices, as opposed to the physical hardware.

SSD (Solid State Drive)

Fast, modern storage with no moving parts — upgrading from an old hard drive transforms a slow computer.

SSL / HTTPS

The padlock in your browser — it encrypts the connection between you and a website.

VoIP (Voice over IP)

Making phone calls over the internet instead of a traditional phone line.

VPN (Virtual Private Network)

A secure, encrypted connection that keeps your internet activity private, especially on public Wi-Fi.

Vulnerability

A weakness in software or a system that attackers can exploit — patching closes them.

Wi-Fi

Wireless internet access within your home or office.

Zero-day

A brand-new security flaw that’s being exploited before a fix exists.

Accessibility & AI terms

AI hallucination

When an AI confidently gives an answer that’s actually wrong or made up — always check anything important.

Business continuity

Planning so your business keeps running, or recovers fast, if IT, premises or staff are disrupted.

Copilot

Microsoft’s built-in AI assistant in Windows and Microsoft 365 that helps you write, summarise and get things done.

Dictation / voice control

Typing or controlling your computer by speaking, instead of using a keyboard or mouse.

High contrast

A display mode with strong colour differences (such as white on black) that’s easier to read.

LLM

Large Language Model — the kind of AI behind tools like ChatGPT and Copilot that understands and writes text.

Magnification

Built-in tools that enlarge part of the screen to make it easier to see.

Prompt

The instruction or question you type into an AI tool to tell it what you want.

RTO / RPO

Recovery Time / Recovery Point Objective — how fast you need to be back up, and how much data you can afford to lose, after a disaster.

Screen reader

Software that reads what’s on screen aloud, helping people with little or no sight use a computer.

Come across a term we haven’t covered? Ask us — we love explaining things in plain English.