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Guide · Reference

The Plain-English AI Glossary

Reference — dip in as neededUpdated 27 October 2026

How to use this: nobody reads a glossary cover to cover. Bookmark it, and when an article, salesperson or quote throws a term at you, look it up here in plain English. If a term you've met isn't here, tell us and we'll add it.

01The basics

AI (Artificial Intelligence)
The umbrella term for software that does things which normally need human intelligence — understanding language, recognising images, making predictions. Today, when someone says "AI" they almost always mean the generative kind below.
Machine learning
Software that learns patterns from examples rather than following hand-written rules. The engine room of all modern AI.
Generative AI
AI that creates things — text, images, code, audio — rather than just sorting or scoring them. ChatGPT writing your email is generative AI; your bank flagging a dodgy transaction is the older kind.
LLM (Large Language Model)
The technology behind ChatGPT and its rivals: a program trained on vast amounts of text to predict what words come next, which in practice lets it draft, summarise and converse. Our AI basics guide explains how.
Model
One specific trained AI — the thing that actually does the work. Providers offer several models at different speed/capability/price points, like engine options in the same car.
ChatGPT, Claude, Gemini, Copilot
Brand names, not technologies — products from OpenAI, Anthropic, Google and Microsoft respectively, all built on LLMs. Hoover vs Dyson, not hoover vs washing machine.

02Using the tools

Prompt
Whatever you type into an AI tool. The single biggest factor in the quality of what comes back — think of it as a briefing, not a search query.
Prompt engineering
The (overdressed) name for writing good prompts: giving the AI a role, audience, tone and constraints. A skill learned in hours, not years.
System prompt
Standing instructions a tool follows before it reads anything you type — "you are a helpful assistant for a plumbing firm; never promise prices." How custom AI assistants get their personality and rules.
Context window
The AI's working memory for your conversation. Everything you've said has to fit in it; very long chats can push early material out, which is why the AI sometimes "forgets".
Token
The chunks of text (roughly word-fragments) an AI actually reads and writes — about 750 words per 1,000 tokens. Mostly invisible to you, but it's the unit AI usage is measured and billed in.
Hallucination
When an AI states something false with complete confidence — an invented statistic, a non-existent court case. Not a glitch but a built-in tendency, and the reason a human checks anything that matters.
Training / training data
The process (and the mountain of text) used to build a model in the first place. Important for you because some free tools use what you type as future training data — see the data section below.
Knowledge cut-off
The date a model's training data ends. It knows nothing after that date unless it searches the web — so ask for sources on anything recent.
Fine-tuning
Taking an existing model and giving it extra training on specific material so it gets better at one job. Rarely needed for small businesses — good prompts and RAG (below) usually get there far more cheaply.
Multimodal
A model that handles more than text — it can look at images, listen to audio, or read documents you upload. Most of the big tools now are.
Reasoning / thinking model
A model (or a mode you switch on) that works through a problem step by step before answering. Slower, but noticeably better at numbers, logic and multi-step tasks.
Memory
A feature that lets an AI tool remember facts about you across separate conversations — your business, your preferences. Different from the context window, and worth checking what it's keeping.

03Beyond the chatbox

Agent
An AI given tools and permission to do multi-step tasks — check the calendar, send the email, update the spreadsheet — rather than just answer questions. We've a whole guide: What Is an AI Agent?
Automation / workflow
A chain of automatic steps triggered by an event: "when a form is submitted → add to spreadsheet → send confirmation." Works with or without AI in the chain; the AI adds judgement to the plumbing.
n8n, Make, Zapier
The popular workflow platforms — the plumbing kits used to build automations and agents by connecting your existing apps together.
API
The connector that lets one piece of software talk to another — how your booking system talks to your calendar, and how custom tools talk to AI models. If a quote mentions "API access", it means software talking to software, no human in the chatbox.
Integration
Any connection between two systems so data flows without retyping. "Does it integrate with Xero?" is asking "will these two talk to each other?"
RAG (Retrieval-Augmented Generation)
A technique where the AI looks things up in your documents before answering, instead of relying on its general training. How "chat with your own company handbook" tools work — and the standard fix for hallucinated facts.
Chatbot
Any program you converse with. The word covers everything from the rigid button-menu bots on retail websites to full LLM assistants — so when someone sells you "a chatbot", ask which kind.
Connectors
Ready-made links that let an AI assistant read and act on your other apps — email, calendar, cloud files, CRM. How a chatbot starts to become an agent without a custom build.
MCP (Model Context Protocol)
An open standard for plugging AI tools into other software, so one connector works with many AI assistants. If a supplier says their product "supports MCP", it means AI tools can connect to it.
AI search / AI Overviews
Answers written by AI at the top of search results, or given directly by tools like ChatGPT, instead of a list of links. Increasingly how customers find businesses — see Getting Found When Customers Ask AI.
Vibe coding
Building software by describing what you want and letting AI write the code. Great for prototypes and simple sites; risky for anything handling customer data or money without an expert check. See our websites guide.

04Data & safety

Personal data
Anything that can identify a living person — names, emails, phone numbers, addresses. The stuff GDPR cares about, and the stuff that shouldn't go into free AI tools. Full picture: Is AI Safe to Use With My Business Data?
GDPR / UK GDPR
The data protection law. It says nothing about AI specifically — but if personal data goes into an AI tool, the law applies exactly as it would for any other software.
Data processing agreement (DPA)
The contract in which a provider commits to handling your data properly on your behalf. Business-tier AI tools include one; free consumer tiers generally don't — which is most of the safety difference.
Training opt-out
A setting (or contractual promise) that stops a provider using your conversations to train future models. Standard in business tiers; worth checking in free ones.
Shadow AI
Staff using AI tools privately, without telling anyone — usually on personal phones. You carry the data risk without the open benefit; the fix is permission with rules, covered in our adoption guide.
Anonymisation
Stripping identifying details out before text goes into a tool ("draft a payment reminder" needs no customer name). The cheapest data protection there is.
Human in the loop
A design where a person approves the AI's work before it takes effect — the email queued for sign-off rather than sent. The hallmark of automation built by grown-ups.
Guardrails
The limits built around an AI system: what it may access, what it may do without approval, what it must refuse. The agent equivalent of "no signing authority".
Automated decision-making
A decision about a person made entirely by software, with no human involved — rejecting an application, refusing credit. UK law allows it with safeguards: people must be told, and be able to challenge it and ask for a human review.
Data (Use and Access) Act 2025
The 2025 update to UK data protection law, mostly in force since February 2026. It amends UK GDPR rather than replacing it — loosening some rules on automated decisions and requiring a data protection complaints process.
Deepfake / voice cloning
AI-generated video, images or audio imitating a real person. Now cheap enough that scammers use cloned voices of bosses or suppliers to request urgent payments — always verify payment changes through a number you already know. More in our AI scams guide.

05Buying & running

Free / Plus / Team / Enterprise tiers
The typical product ladder for AI tools. The jump that matters for business isn't features — it's the data handling: Team and above is usually where the no-training commitments and DPAs live.
Open-source model
A model whose files are published for anyone to download and run — meaning it can run on hardware you control, with data never leaving the building.
Self-hosted / local AI
Running a model on your own computer or server instead of a provider's cloud. More effort, total data control — the option for the especially cautious.
Cloud
Someone else's computers, rented over the internet. Where almost all AI actually runs, because the hardware is expensive.
GPU
The specialist chip AI runs on (originally built for video games). Mentioned here only so the headlines about chip shortages make sense — you'll likely never buy one.
SaaS (Software as a Service)
Software you rent monthly and use in a browser rather than buy outright — the model nearly every AI tool follows.
AI washing
Marketing that labels a product "AI-powered" when the AI does little or nothing. Ask what the AI actually does, and what the product does without it.

Met a term that isn't here?

Send it over and we'll add it — and if you'd rather have all of this explained in person, with examples from your own business, that's exactly what our AI training is for.

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