Glossary

Andy Bright

Director of Product and Technology

This glossary explains the terms used in this guide. Each entry links to the chapter that explains the term in more detail. The technical SEO guide's glossary explains more technical terms, such as canonical tags and status codes.

A

Accuracy is the share of answers to your branded questions that describe your business correctly. See measurement.

AEO (answer engine optimisation) and GEO (generative engine optimisation) are two names for the same work: making sure AI assistants mention your business, describe it correctly and link to your website. See how AI answers work.

Agentic Commerce Protocol (ACP) is OpenAI's open standard for how shops share product data, and handle checkout, with ChatGPT. See shopping and apps.

AI agent is an AI tool that uses websites on someone's behalf, for example to compare products, fill in forms or buy something. See shopping and apps.

AI assistant is a program you can ask questions in ordinary language, which writes an answer for you, such as ChatGPT, Gemini, Claude, Copilot or Perplexity. See each assistant.

AI Assistant channel is the group in Google Analytics 4 for visits from AI assistants such as ChatGPT, Gemini and Copilot. It doesn't include visits from Google's AI Overviews and AI Mode. See measurement.

AI Mode is Google's chat-style search, where you ask questions and get AI-written answers with links. In May 2026 Google began combining it with AI Overviews. See each assistant.

AI Overviews are the AI-written summaries at the top of some Google search results. See each assistant.

AI Performance report is the report in Bing Webmaster Tools that shows how often Copilot and Bing's AI summaries cite your pages. See measurement.

AI recommendation poisoning is Microsoft's name for hiding instructions in "Summarize with AI" buttons and links, to make an assistant remember a business as trusted or recommend it. It's a form of prompt injection. See what to avoid.

Answer engine is another name for an AI assistant or AI search feature, because it gives an answer instead of a list of links. See how AI answers work.

API (application programming interface) is a connection that lets software send questions to an AI model directly, without using the app people use. Answers from an API can differ from answers in the app. See measurement.

App, in ChatGPT, is a connection to another company's service that ChatGPT can use on someone's behalf. Since July 2026 apps are listed as part of plugins. See shopping and apps.

B

Backlink is a link from another website to yours. See other websites.

Bing Places is Microsoft's free listing for businesses that serve customers in person, its equivalent of Google Business Profile. See regulated, local and international businesses.

Bing Webmaster Tools is Microsoft's free tool that shows site owners how Bing sees their site, including its AI Performance report. See measurement.

Brand agent is a chat assistant a business runs about its own products, such as Google's Business Agent or Microsoft's Brand Agents. See shopping and apps.

Branded question is a question that names your business, such as "is Fernhill Coffee any good?". It shows whether assistants describe you correctly. See measurement.

C

CDN (content delivery network) is a service such as Cloudflare that delivers a website's pages quickly and often filters visitors too. It can block AI crawlers. See the technical SEO guide's glossary.

Channel, in Google Analytics, is a group of visits that arrive the same way, such as Organic Search, Email or Referral. See measurement.

Citation is a link to a page that an AI answer shows as one of its sources. See how AI answers work.

Citation rate is the share of answers that link to at least one of your pages. See measurement.

Citation Share is a figure in Bing Webmaster Tools that shows your share of the citations for a grounding query. See measurement.

Clean session is a way of asking an assistant a question without your own history, memory or settings, for example in a private browser window where you're not signed in. See measurement.

Commodity content is Google's name for pages that repeat common knowledge anyone could have written. AI assistants have little reason to cite it. See content.

Connector is Anthropic's name for what ChatGPT calls an app: a connection to another company's service that Claude can use on someone's behalf. See shopping and apps.

Content gap is a question your customers ask where AI assistants name competitors and not you. See the 90-day plan.

Correlation is a measure of how closely two things rise and fall together, from −1 (one falls exactly as the other rises), through 0 (no relationship), to 1 (they rise together exactly). It doesn't show that one causes the other. See other websites.

Crawler is a program that visits web pages and copies them, for a search engine's index or an AI company. See how AI answers work.

Custom channel group is a set of channel rules you write yourself in Google Analytics, for example to catch AI assistants its own channel misses. See measurement.

E

Earned media is what independent people publish about you, such as reviews, news articles and lists of recommendations. AI answers rely on it heavily. See other websites.

F

Fact sheet is one document that holds the true version of the facts about your business, which everyone who describes it copies from. See describing your business.

Fan-out is short for query fan-out.

Firewall is security software that decides which visitors a website accepts. It can block AI crawlers even when robots.txt allows them. See shopping and apps.

G

Generative AI performance report is a report in Google Search Console that shows how often links to your site appeared in AI Overviews and AI Mode. See measurement.

Google Business Profile is the free listing that shows a business's address, opening hours, photos and reviews in Google Search and Maps. With a few exceptions, only businesses that meet customers in person can have one. See regulated, local and international businesses.

Google Merchant Center is Google's free service where shops upload details of their products. See shopping and apps.

Google Search Console is Google's free tool that shows site owners how Google sees their site, including a report on its AI features. See measurement.

Grounding, also called retrieval-augmented generation or RAG, means writing an answer from pages fetched for the question, instead of from the AI model's memory alone. See how AI answers work.

Grounding queries are the searches Bing's AI ran that led it to cite your pages. Bing Webmaster Tools shows a sample of them. See measurement.

H

Hidden text is text on a page that people can't easily see but machines can read, such as white text on a white background. Google treats it as spam when it's there to manipulate search engines. See what to avoid.

hreflang is a tag in a page's code that tells search engines which language and country the page is for. See the technical SEO guide's international SEO chapter.

I

Impressions, in Google Search Console, count how often a link to your site was shown. See measurement.

Incentivised review is a review written in return for something, such as a discount or gift card. Review sites have different rules about them. See other websites.

Index is a search engine's database of web pages. An assistant that searches Google's index can only use pages that are in it. See each assistant.

K

Knowledge panel is the box of information about a business, person or place that Google sometimes shows beside its search results. See describing your business.

L

Large language model (LLM) is the kind of computer program behind AI assistants, trained on huge amounts of text to predict and write language. See how AI answers work.

llms.txt is a proposed file that describes a website for AI tools. Google Search ignores it. See the technical SEO guide's section on llms.txt.

M

Margin of error is how far a measured figure could move by chance, if you measured again and nothing had changed. See measurement.

Mention is the name of a business, product or person in the text of an AI answer. See how AI answers work.

Mention rate, sometimes called visibility, is the share of answers that name your business. See measurement.

Microsoft Merchant Center is Microsoft's service where shops upload product feeds, which help inform Copilot's answers. See shopping and apps.

Model Context Protocol (MCP) is an open standard for connecting AI assistants to other software. Most ChatGPT apps and Claude connectors use it. See shopping and apps.

O

Owned media is what you publish yourself, such as your website. See other websites.

P

Paid media is advertising. See other websites.

Plugin, in ChatGPT, is a package that can contain one or more apps and written instructions for particular tasks, listed in ChatGPT's Plugin Directory. See shopping and apps.

Product feed is a file that lists every product you sell, with its price, stock level, photos and other details, which you upload to a shopping platform. See shopping and apps.

Prompt is the question or request someone types into an AI assistant. See how AI answers work.

Prompt injection means hiding instructions in content so that an AI system follows them, instead of doing what its user asked. See what to avoid.

Prompt set is the fixed list of questions you ask AI assistants again and again to measure how they describe you. See measurement.

Prompt volume is how often people ask an AI assistant a particular question. No major AI company except Microsoft shares this data, so the figures that tools sell are estimates. See measurement.

Protocol is an agreed set of rules that lets different companies' systems work together. See shopping and apps.

Q

Query fan-out is when an AI assistant turns one question into several related searches and runs them at the same time. See how AI answers work.

R

RAG (retrieval-augmented generation) is another name for grounding.

Ranking is the order in which a search engine lists pages for a search. See each assistant.

Recommendation rate is the share of answers that recommend your business for the person's need, rather than just listing it. See measurement.

robots.txt is a short file on a website that tells crawlers which pages they may visit. See each assistant.

Roundup is an article that lists and compares the options in a category, such as "The 10 best coffee subscriptions in the UK". It's also called a "best of" list. See other websites.

S

Scaled content abuse is Google's name for publishing large numbers of pages mainly to rank, rather than to help readers. See what to avoid.

SEO (search engine optimisation) is the work of getting your pages to appear in search engines such as Google. See how AI answers work.

Server logs are the record a website's server keeps of every request, including which crawler asked for which page. See measurement.

Share of voice is your share of all the mentions of you and the competitors you track. See measurement.

Spam policies are Google's rules against tricking its search results. In May 2026 Google made clear that they also cover attempts to manipulate its AI answers. See what to avoid.

Structured data is code you add to a page to describe its content in a standard format that machines can read. See describing your business.

T

Training crawler is a crawler that collects text to train future AI models, such as GPTBot or ClaudeBot. It's separate from the crawlers that fetch pages for answers. See the technical SEO guide's crawlability chapter.

Training data is the text an AI model learned from before it was released. What a model learned stays the same until a new version is released. See how AI answers work.

U

Unbranded question is a question that doesn't name your business, such as "what's a good coffee subscription in the UK?". It shows whether assistants recommend you to people who haven't heard of you. See measurement.

Universal Cart is Google's shopping basket in Search and the Gemini app, launched in the US in October 2026, which lets people save products from several retailers and, for many shops, pay without leaving Google. See shopping and apps.

Universal Commerce Protocol (UCP) is an open standard, led by Google, for buying inside AI assistants. Since October 2026 it powers checkout in Universal Cart, in Google Search and the Gemini app, in the US. See shopping and apps.

User-triggered fetcher is a program an AI company uses to fetch a page while answering a person's question, such as ChatGPT-User or Claude-User. See shopping and apps.

W

Wikidata is a free database of facts about people, places, organisations and things, run by the same foundation as Wikipedia. See describing your business.

Y

YMYL (Your Money or Your Life) is Google's term for subjects where bad information could harm people's health, finances or safety, or society's well-being. See regulated, local and international businesses.