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GEO
Generative engine optimization # - Work aimed at getting a page or product cited inside an answer that a large language model generates — ChatGPT, Perplexity, Gemini or Google’s AI Mode. Google’s own AI-optimization guide treats it as part of ordinary SEO rather than a separate discipline.
- See also: AEO · AI SEO · AI visibility
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AEO
Answer engine optimization # - Work aimed at being the extracted answer to a question, across any surface that answers directly: featured snippets, People Also Ask, voice assistants and knowledge panels. Broader than GEO, and older — it predates generative models by roughly a decade.
- See also: GEO · AI Overviews
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AIO
AI optimization # - An informal umbrella for GEO and AEO together. It has no agreed technical definition and no standards body behind it; different agencies use it to mean noticeably different scopes of work.
- See also: GEO · AEO · AI SEO
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LLMO
Large language model optimization # - Another informal synonym for GEO, used mainly in vendor marketing. It carries the same meaning as generative engine optimization and no additional technical content, so a proposal built around the term is worth reading for what it actually specifies.
- See also: GEO
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AI SEO
# - A catch-all term with no fixed technical meaning. Depending on who is speaking it can mean optimizing for AI search surfaces, using AI tools to produce SEO work, or both. Ask which is meant before buying it.
- See also: GEO · AEO
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AI visibility
# - Whether a store and its products get mentioned, cited or linked when someone asks an AI assistant what to buy and where. Used here as the plain-language name for the outcome that GEO and AEO describe as methods.
- See also: GEO · AEO
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RAG
Retrieval-augmented generation # - The technique behind most AI search answers: the model retrieves documents from an index or the live web, then writes its answer grounded in what it retrieved. It is why crawlability and clean, quotable pages matter more than writing style.
- See also: Grounding · Query fan-out
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Query fan-out
# - The practice of an AI search system turning one user question into several background searches, then synthesising a single answer from the combined results. A store can therefore surface for a phrasing that appears nowhere in its own copy.
- See also: RAG · AI Mode
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Grounding
# - Tying a generated answer to retrieved sources so claims can be attributed rather than invented. Grounded answers are the ones that carry citations, which is the only way a store gets a link out of an AI answer.
- See also: RAG
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Merchant feed
# - A structured file listing a catalogue — id, title, price, availability, GTIN, brand, shipping — submitted to a platform rather than crawled. Google names Merchant Center feeds as the route to product visibility in its generative AI features.
- See also: GTIN · Agentic Commerce Protocol
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GTIN
Global Trade Item Number # - The numeric identifier printed as a product’s barcode; EAN-13 is the common European form. It lets an engine match one shop’s listing to the same product elsewhere, which is how a price becomes comparable and therefore trustworthy.
- See also: Merchant feed
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Agentic Commerce Protocol
# - An open specification through which an AI assistant creates and completes a purchase in a merchant’s own store on the buyer’s behalf. It underpins ChatGPT Instant Checkout, which as of August 2026 is live for US and UK merchants only.
- See also: Merchant feed
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AI Overviews
# - Google’s generated summary shown above the classic blue links for many queries, with links to the sources it drew on. Distinct from AI Mode, which is a separate conversational surface rather than a block on the results page.
- See also: AI Mode · AEO
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AI Mode
# - Google’s conversational search surface, where a query becomes a dialogue and the system may fan out into multiple background searches before answering. Product results shown there draw on Merchant Center data.
- See also: AI Overviews · Query fan-out
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GPTBot
# - OpenAI’s crawler used to collect web content for training and some retrieval. Blocking it does not remove a site from ChatGPT’s search answers — that is OAI-SearchBot — but most "block AI" plugins disallow both at once.
- See also: OAI-SearchBot · llms.txt
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OAI-SearchBot
# - The OpenAI crawler that powers search and shopping answers in ChatGPT. It does not train models. Disallowing it is the single most damaging robots.txt rule for a shop that wants to be recommended.
- See also: GPTBot
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PerplexityBot
# - Perplexity’s crawler, which indexes pages so they can be cited in its answers. Perplexity-User is the companion agent that fetches a page when a person follows a link during a conversation.
- See also: OAI-SearchBot
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ClaudeBot
# - Anthropic’s crawler for Claude, used to collect web content. Claude-SearchBot is the related agent behind search results, and Claude-User fetches a page in response to something a person asked during a conversation. A robots.txt rule naming one does not cover the others.
- See also: OAI-SearchBot
Reference
Glossary
Short, sourced definitions of the terms used around AI search and ecommerce. Definition first, no marketing. Written so an assistant can quote it.