AEO & GEO glossary
Every term that matters in AI search — defined, with a link to the full explainer where one exists. New entries land here as we ship them.
Concepts
The foundational ideas — start here if you're new to AEO.
AEO (Answer Engine Optimisation)
Getting your brand named, cited and recommended inside AI answers from ChatGPT, Claude, Perplexity, Gemini and Google AI Overviews.
GEO (Generative Engine Optimisation)
The technical and content layer that makes a site readable, parseable and trustworthy to generative AI systems.
AEO vs SEO
Where blue-link optimisation ends and answer-inclusion optimisation begins — and why the same site needs both.
AI search ranking
How AI answer engines (ChatGPT, Claude, Perplexity, Gemini, Google AI Overviews) decide which brands and sources to feature in their answers. Different mechanics from classical Google ranking.
AI search rankings
AI search rankings track how often AI engines (ChatGPT, Claude, Perplexity, Gemini, Google AI Overviews) name a brand in their answers and cite the brand's domain as a source, across a fixed set of buyer-intent queries.
AI search vs SEO
Where SEO measures ranking in a list of blue links, AI search measures whether your brand is named and cited in the synthesised answer. Different user behaviour, different metrics.
Brand AI answer rankings
Brand-level rankings of which companies AI engines name and cite most often in answers to category-relevant buyer questions. The AI-era equivalent of a G2 listicle.
GEO (full form)
GEO stands for Generative Engine Optimisation — the practice of optimising content so generative AI engines cite and recommend your brand in their synthesised answers.
Google AI surfaces
Google's two AI search products — and the structural differences that shape how you measure visibility on each.
AI Overview
Google's inline AI panel that appears above the regular search results. Renders on ~25–48% of queries depending on intent.
AI Mode
Google's standalone AI search experience (
?udm=50). Always renders a full conversational answer with 15–30 citations.
AI Overview rollout status (where it is live, where it isn't)
Google AI Overview is live across roughly 100+ countries as of mid-2026, on roughly 25 to 48 percent of eligible queries, with rollout still expanding. Specific availability depends on your account, region, query type, and whether you're signed in.
AI Overview vs Knowledge Panel
AI Overview is a generative, per-query answer synthesised from live web sources. Knowledge Panel is a structured, per-entity card pulled from Google's Knowledge Graph. Different pipelines, different signals.
How to turn on AI Overview
AI Overview cannot be manually turned on — Google decides per-query based on query type, region, account signals, and Search Labs status. There is no user toggle.
How each engine works
Engine-by-engine breakdowns of how citations get picked and why some brands consistently win.
ChatGPT citations
The source links ChatGPT attaches to answers when it uses live web search. They are the URLs ChatGPT treats as evidence for what it told the user.
How ChatGPT chooses citations
ChatGPT chooses citations by running a web search via its tool-use system, then re-ranking results through its own relevance model before generating the answer.
How Claude Web Search works
Claude's web search is a tool-use capability where the model decides when to query the web, what to query for, and which results to use as evidence. Often runs multiple search hops per answer.
How Gemini grounding works
Gemini grounding lets the model anchor answers in real web sources via Google's groundingMetadata. When enabled, Gemini returns the answer alongside a structured list of source URLs.
How Google AI Overviews pick sources
Google AI Overview picks sources via a retrieval pipeline that overlaps with classical Google ranking but weights different signals — particularly structured data, freshness, and passage extractability.
How Perplexity ranks sources
Perplexity is a search-native AI — every answer is grounded in live web sources with inline numbered citations. It weights freshness, factual density, and primary-source signals more heavily than other AI engines.
Most cited domains in ChatGPT
The domains ChatGPT cites most across categories — consistently Reddit, Wikipedia, G2, Capterra, TechCrunch, Forbes, and the brand's own site, plus category-specific trade publications.
Most cited domains in ChatGPT
The websites ChatGPT pulls from most often when its web search tool runs. Dominated by encyclopedic sources, top trade publications, and major review aggregators per category.
Metrics
The four numbers that matter when you measure your AI visibility.
AI Overview mention
An AI Overview mention is when your brand name appears in the synthesised answer prose, distinct from a citation where only your URL appears in the source list.
AI visibility vs citation rate
The two primary AEO metrics measure different things: visibility is whether the AI names your brand in the answer, citation rate is whether it links your domain as a source. A brand can be high on one and low on the other.
Brand AI search score
A composite metric that summarises how prominently AI engines feature your brand across a category. Typically combines visibility (named in answers) and citation rate (cited as source) into a single 0 to 100 number.
Brand hallucination prevention
When AI engines fabricate false claims about your brand — invented features, wrong pricing, made-up partnerships. Caused by information vacuums where authoritative content is missing.
Citation rate (AI search metric)
Percentage of AI answers that include your domain in the source citation list. Measures who the AI trusts as evidence.
Share of voice in AI answers
Your brand visibility relative to the other brands the AI mentions in the same answer set. The most defensible AEO metric — normalises for query selection bias.
Visibility (AI search metric)
Percentage of AI answers that name your brand in the response prose. Measures who the AI recommends to the buyer.
Tactics
What you actually do to move the metrics above.
AEO checklist
The 20-item priority list — foundations, content, entity signals, ongoing tactics. Work in order.
What is llms.txt?
The emerging markdown manifest standard for AI crawlers, similar to robots.txt for search.
AEO tools comparison
Honest comparison of monitoraeo, Otterly.ai, Profound, Athena, Goodie and others.
AI answer engine monitoring
The practice of continuously measuring how AI answer engines (ChatGPT, Claude, Perplexity, Gemini, Google AI Overviews) describe and cite your brand, tracking change over time.
AI Overview tracking API
An AI Overview tracking API captures Google AI Overview content for a fixed query set on a schedule, then exposes the data (text, citations, brand mentions, score deltas) for ingestion into a dashboard or pipeline. Different from a one-shot 'AI Overview API' (which just returns the latest AIO content for a query) in that the tracking layer is the product.
AI reputation management
AI reputation management is the practice of monitoring and shaping how AI answer engines describe a brand: what they say, what they get wrong, and which sources they cite. The AI-search analogue to classical online reputation management.
AI visibility tools (the AEO tooling landscape)
AI visibility tools are software platforms that track how AI answer engines (ChatGPT, Claude, Perplexity, Gemini, Google AI Overviews) describe a brand, name it in answers, and cite its domain. The AEO category, equivalent to what rank trackers are to classical SEO.
Brand hallucination monitoring
The detection pass that catches fabricated AI claims about your brand after they appear — recurring factual queries across engines, compared against ground truth.
ChatGPT citation analysis
The practice of measuring how often, and on which queries, your domain is cited as a source in ChatGPT answers. The diagnostic step that comes before any AEO work.
Google AI Overview API
There is no official public API for Google AI Overview. Programmatic access goes through third-party Google search APIs that scrape the rendered SERP — SearchApi.io, SerpApi, Apify, DataForSEO — at roughly $2-10 per 1,000 queries.
llms.txt examples + templates
Real-world examples of llms.txt files from sites that publish them, plus a working template you can copy. Updated as the standard evolves.
Structured data for AI engines
Structured data (JSON-LD) tells AI engines exactly what your page is about in a format they can parse unambiguously. The schemas that move the needle for AI citations are different from the schemas that win SEO rich results.
See it on your own brand
The fastest way to understand any of these terms is to see them measured against your own domain. The free preview gives you a real-data snapshot in under a minute.