AI Search Glossary

Back to blog

A

Commerce

Agentic commerce

Agentic commerce is shopping in which an AI agent acts for a person: it finds and compares products and can complete the purchase, sometimes without the shopper opening the merchant's website. Open protocols such as the Agentic Commerce Protocol from OpenAI and Stripe and Google's Universal Commerce Protocol give agents and merchants a shared way to handle the order.

Full definition
Measurement

AI brand mentions

AI brand mentions are the times an AI engine like ChatGPT or Google AI Overviews names your brand in an answer. A mention counts whether or not the answer links to your website. That's the difference from a citation, where the engine credits a specific page as its source.

Also called: LLM brand mentions, mention rate

Full definition
Measurement

AI brand monitoring

Keeping watch on what AI engines say about your brand and which sources they draw on when they say it.

Also called: AI search monitoring

Read the guide
Measurement

AI brand sentiment

The tone an AI engine takes when it describes your brand: positive, neutral, or negative, and the specific claims behind that tone.

Read the guide
Measurement

AI citations

AI citations are the links an AI engine attaches to its answer to show which web pages the information came from. Each citation credits a specific URL. A brand mention is different: the engine names a company in the text, even when it doesn't link to that company's site.

Also called: citation frequency, citation rate, LLM citations

Full definition
Technical

AI crawlers

Bots run by AI companies that fetch web pages, either to collect training data or to retrieve live sources for an answer.

Also called: AI bots, LLM crawlers

How AI search works

AI hallucination

A confident but false statement from an AI model, such as a price your product never had or a source that doesn't exist.

Also called: hallucination

Measurement

AI referral traffic

AI referral traffic is website visits that arrive when someone clicks a link inside an AI-generated answer, such as a cited source in ChatGPT, Perplexity, Gemini, Claude, or Microsoft Copilot. Analytics tools identify it by the referring domain or by a UTM tag, like the utm_source=chatgpt.com parameter ChatGPT adds to its links.

Also called: LLM referral traffic, AI traffic

Full definition
Disciplines

AI search optimization

The umbrella term for improving how a brand appears across AI search surfaces, from ChatGPT and Perplexity to Google AI Overviews and AI Mode.

Also called: AI SEO

Read the guide
Measurement

AI share of voice

AI share of voice is the percentage of all brand mentions in AI-generated answers that belong to your brand, measured across a fixed set of prompts. Each brand counts once per answer it appears in. If brands are named 200 times across your tracked answers and 50 of those mentions are yours, your share of voice is 25%.

Also called: AI SOV, share of voice in AI search

Full definition
Measurement

AI visibility

How often AI engines bring up your brand when people ask about your category, and how accurately they describe it.

Also called: AI search visibility, AI brand visibility

Read the guide
Measurement

AI visibility score

An AI visibility score is the percentage of tracked AI answers that mention your brand. You divide the answers that name you by every answer in your tracked prompt set, including answers that name no brand at all. If your brand appears in 30 of 100 tracked answers, your AI visibility score is 30%.

Full definition
Measurement

AI visibility tracking

Measuring AI visibility over time by running the same prompts across engines and comparing mentions, citations, and positions from run to run.

Read the guide
Engines and surfaces

Answer engine

A search tool that replies with a written answer instead of a list of links. ChatGPT, Perplexity, Gemini, and Google AI Overviews are all answer engines.

Also called: AI answer engine

B

Measurement

Branded vs unbranded prompts

Branded prompts are AI questions that name your company, such as "Is Acme good for agencies?" Unbranded prompts describe a need without naming any brand, such as "best project software for agencies." Tracking unbranded prompts shows whether AI engines recommend you to buyers who don't know you yet.

Also called: branded prompts, unbranded prompts, non-branded prompts

Full definition

C

Engines and surfaces

ChatGPT

OpenAI's AI assistant. It answers from its training data and, when search is used, from live web results it retrieves and cites.

Read the guide
Engines and surfaces

Claude

Anthropic's AI assistant. It can search the web and cite sources when a question needs current information.

How AI search works

Content chunking

Content chunking is the way AI search systems split a web page into smaller passages so each one can be retrieved and quoted on its own. The term also describes writing pages in clear, self-contained sections, so any passage an engine pulls out still makes sense without the rest of the page.

Also called: chunking, passage ranking, passage slicing

Full definition
Disciplines

Content freshness

Signals that tell search engines and AI systems a page is current, such as a visible update date and recent data.

Read the guide
How AI search works

Context window

The maximum amount of text, measured in tokens, that a model can consider at once, including the prompt, any retrieved sources, and its own reply.

D

Disciplines

Domain authority

A score created by Moz that estimates how likely a domain is to rank, based mostly on its backlinks. It's a third-party metric that Google doesn't use.

E

Disciplines

E-E-A-T

Experience, expertise, authoritativeness, and trustworthiness: the qualities Google's quality rater guidelines use to judge whether content deserves to be trusted.

Also called: EEAT, experience, expertise, authoritativeness, trustworthiness

Read the guide
Disciplines

Earned media

Coverage of your brand on sites you don't own, such as reviews, press, forums, and third-party lists. AI engines lean heavily on these sources when they recommend brands.

How AI search works

Embeddings

Embeddings are lists of numbers that represent the meaning of a piece of content, such as a paragraph of text or an image. Content with similar meaning gets similar numbers, so a system can find a relevant passage even when it shares no words with the question. Embeddings are what make semantic search and AI retrieval work.

Also called: vector embeddings

Full definition
How AI search works

Entity SEO

Making sure search engines and AI models recognize your brand as a distinct entity, with consistent facts about what it is and what it's connected to.

Also called: entity optimization

F

G

Engines and surfaces

Gemini

Google's family of AI models and the name of its standalone AI assistant. Gemini models also power AI Overviews and AI Mode.

Disciplines

Generative engine optimization (GEO)

Optimizing content to be included and credited in answers written by generative AI systems. In practice the term is used almost interchangeably with AEO.

Also called: GEO

Engines and surfaces

Google AI Mode

A conversational search mode inside Google Search that answers with an AI-written response and supports follow-up questions.

Also called: AI Mode

Read the guide
Engines and surfaces

Google AI Overviews

AI-generated summaries that appear above the organic results in Google Search, with links to the pages they draw on.

Also called: AI Overviews, AIO

Read the guide
Technical

GPTBot

OpenAI's crawler for collecting model training data. ChatGPT search uses a separate crawler, OAI-SearchBot, so blocking GPTBot in robots.txt doesn't remove you from ChatGPT search results.

Also called: OAI-SearchBot, ChatGPT-User

How AI search works

Grounding

Grounding in AI means tying a language model's answer to specific source material, such as live search results or a company's own documents, so the model isn't relying only on what it learned in training. A grounded answer can point to its sources, which is why AI search engines show citations.

Also called: grounding in AI

Full definition

H

K

How AI search works

Knowledge cutoff

The date after which a model has no training data. Anything newer reaches the model only if it retrieves it from the web at answer time.

Also called: training cutoff

How AI search works

Knowledge graph

A database of entities and the relationships between them. Google's Knowledge Graph powers knowledge panels and helps AI systems resolve which brand a question is about.

L

How AI search works

Large language model (LLM)

An AI model trained on large amounts of text to predict and generate language. LLMs are the engines inside ChatGPT, Claude, Gemini, and most AI search tools.

Also called: LLM

Disciplines

LLM SEO

Search optimization aimed at large language models, covering both your own pages and the third-party sources models draw on when they mention you.

Also called: LLM optimization, LLMO

Read the guide
Technical

llms.txt

llms.txt is a proposed standard for a markdown file at a website's root (example.com/llms.txt) that summarizes the site and links to its most useful pages for language models. Jeremy Howard of Answer.AI proposed it in September 2024. Google says its search ignores the file, and no other major AI search engine has said it uses one.

Full definition

M

Engines and surfaces

Microsoft Copilot

Microsoft's AI assistant, built into Windows, Edge, Bing, and Microsoft 365. It grounds web answers in Bing search results.

Also called: Copilot

Technical

Model Context Protocol (MCP)

The Model Context Protocol (MCP) is an open standard for connecting AI applications to outside tools and data. An MCP server describes what it can do in a format any MCP-compatible assistant understands, so one integration can work across AI apps like Claude and Cursor without custom code for each.

Also called: MCP

Full definition

P

Engines and surfaces

Perplexity

An AI answer engine that searches the web for every query and shows numbered citations beside its answer.

Measurement

Prompt tracking

Prompt tracking is running a fixed set of buyer questions through AI engines like ChatGPT and Perplexity on a schedule, then recording which brands and sources appear in each answer and where they rank. Comparing the same prompts over time shows whether your AI visibility is rising or falling.

Also called: tracked prompts, prompt monitoring

Full definition

Q

How AI search works

Query fan-out

When an AI engine splits one question into several related searches, retrieves results for each, and combines them into a single answer.

Also called: query fanout, fan-out queries

Read the guide

R

How AI search works

Retrieval-augmented generation (RAG)

Retrieval-augmented generation (RAG) is a technique where an AI model first searches a set of documents for passages that match a question, then writes its answer from those passages. Because it looks things up at answer time, the model can use up-to-date information and point to where it came from.

Also called: RAG

Full definition

S

Engines and surfaces

Search Generative Experience (SGE)

Google's 2023 Search Labs experiment with AI-generated answers. It became AI Overviews when Google rolled the feature out in May 2024.

Also called: SGE

Technical

Server-side rendering (SSR)

Building a page's HTML on the server before it is sent, so crawlers that don't run JavaScript, including most AI crawlers, can still read the content.

Also called: SSR, client-side rendering, CSR

Technical

Structured data

Code, usually schema.org JSON-LD, that labels what a page contains, such as a product or an FAQ, in a format machines can parse.

Also called: schema markup, schema.org

T

How AI search works

Tokenization

Breaking text into tokens, the small units of words and characters that language models read and generate.

Also called: tokens

Read the guide
Disciplines

Topical authority

How thoroughly a site covers a subject, judged across all its pages rather than any single one.

U

V

W

Technical

WebMCP

A proposed web standard that lets a website expose actions, such as search or checkout, as tools an in-browser AI agent can call directly.

Read the guide

X

Technical

XML sitemap

A file that lists the URLs on a site you want search engines to crawl, often with the date each was last changed.

Read the guide

Z