Glossary
AI search & AEO glossary
Plain-English definitions of the terms behind AI search - answer engines, citations, crawlers, structured data and the rest. No jargon left unexplained.
- AEO (Answer Engine Optimization)
- Structuring content so AI answer engines can extract it and cite it directly in their answers. Where SEO aims to rank a link, AEO aims to be the source the AI quotes. Learn more →
- GEO (Generative Engine Optimization)
- Optimising content to be surfaced and cited by generative AI search. Used almost interchangeably with AEO; GEO emphasises generative systems specifically. Learn more →
- AI answer engine
- A system that responds to a question with a written answer assembled from sources, instead of a list of links - ChatGPT, Perplexity, Google AI Overviews and Gemini. Learn more →
- AI Overviews
- Google's AI-generated answers that appear above the classic results for many searches, summarising and citing sources rather than only listing links.
- Answer-first
- A writing structure where the opening sentences fully answer the core question on their own, before any preamble - the part an answer engine can lift and quote cleanly. Learn more →
- Citation
- When an AI answer names a source it drew on, often with a link. Being the cited source is the core goal of AEO - the AI-search equivalent of ranking first. Learn more →
- Structured data (schema)
- Machine-readable markup (schema.org, usually JSON-LD) that tells search and AI engines what a page is - an Article, an FAQ, a product - so they can understand and reuse it.
- FAQPage schema
- Structured data that marks up a page's question-and-answer pairs, making them eligible for rich results and easy for an answer engine to extract. Learn more →
- E-E-A-T
- Experience, Expertise, Authoritativeness, Trustworthiness - the qualities Google's raters and systems use to judge whether content is credible and worth surfacing.
- LLM (Large Language Model)
- The type of AI model behind answer engines - trained on vast text to generate human-like responses. ChatGPT, Claude and Gemini are built on LLMs.
- RAG (Retrieval-Augmented Generation)
- A technique where an AI retrieves relevant documents from the live web or a database and uses them to ground its answer - the mechanism behind cited AI search results.
- GPTBot
- OpenAI's web crawler. If your robots.txt blocks it, ChatGPT can't read - or cite - your pages. Allowing it is a prerequisite for OpenAI AI-search visibility. Learn more →
- ClaudeBot
- Anthropic's web crawler, used by Claude. Like other AI crawlers, it's controlled via your robots.txt user-agent rules. Learn more →
- Google-Extended
- The user-agent that controls whether Google may use your content for its AI features. Blocking it opts you out of Google's generative answers. Learn more →
- llms.txt
- A proposed file at your domain root that gives AI models a clean, curated map of your key content. Emerging and optional, not yet universally adopted. Learn more →
- Zero-click search
- A search that's answered on the results page itself - by an AI answer or snippet - so the user never clicks through. It shifts value from the click to the citation. Learn more →
- Featured snippet
- A short answer Google pulls to the top of results from a page. The classic-search precursor to AI answers, and often drawn from answer-first content.
- Knowledge panel
- The box of facts Google shows about an entity - a business, person or brand - drawn from trusted sources and structured data. A signal of recognised authority.
- Canonical URL
- The tag that tells search engines which version of a page is the authoritative one, preventing duplicate-content confusion when the same content sits at several URLs.
- Internal linking
- Links between pages on your own site. They spread ranking authority, help engines understand topic clusters, and guide readers from an answer toward a conversion.
- Perplexity
- An AI answer engine built around search - it answers questions conversationally and cites its sources prominently, making citation especially visible.
Want the concepts, not just the definitions?
Our plain-English guides walk through AEO, GEO and getting cited by AI - or check any page free.