Glossary
AEO, GEO and AI search glossary
The AI search world invented a new vocabulary faster than anyone could keep up. These are 18 plain-English definitions of the terms that actually matter, each one grounded in the docs, including Google's official AI optimization guide. We wrote them the way an answer engine likes to quote: “a clear definition, then why it matters, then what to do.”
How AI search works
- What is RAG (retrieval-augmented generation)? How AI answers from documents it retrieves.
- What is query fan-out? One question becomes many searches behind the scenes.
- What is Google AI Mode? Google's conversational, fully AI search experience.
- What is agentic search? When an AI agent does the searching for the user.
- What is zero-click search? The answer appears, the click never happens.
- What is the great decoupling? Impressions rise while clicks fall.
- What is AI share of voice? How often the machines mention you.
The AI crawlers
- What is OAI-SearchBot? OpenAI's crawler that earns you a ChatGPT citation.
- What is PerplexityBot? Perplexity's crawler for cited sources.
Ranking and quality
- What is E-E-A-T? How Google judges who to believe.
- What is helpful content? Write for people first, machines follow.
- What is topical authority? Depth across a topic beats one keyword page.
- What is passage indexing? Ranking one passage, not the whole page.
- What is a featured snippet? The answer Google lifts to position zero.
Entities and schema
- What is entity SEO? Engines rank things, not just keywords.
- What is sameAs schema? Linking your profiles so a machine knows it's you.
- What is a Wikidata QID? A permanent ID that names your entity.
- What is a knowledge panel? The box that proves Google knows who you are.
Where this fits
These terms run through our two pillars, what is AEO and what is GEO, and the Fix Library that turns them into action. To see which of these concepts your own site is getting wrong, run the free preview with our AEO checker or the full audit at the app.