The AI search visibility vocabulary
Single-source-of-truth definitions for the terms used across AEO, GEO, AI search visibility, and AI crawler analytics. Each entry is published with schema.org/DefinedTerm so language models can extract the definition cleanly.
- DEFINITION
Answer Engine Optimization (AEO)
Answer Engine Optimization (AEO) is the practice of structuring web content so AI search engines like ChatGPT, Perplexity, Gemini, Claude, and Grok can quote, summarise, and recommend it in their answers.
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Generative Engine Optimization (GEO)
Generative Engine Optimization (GEO) is the practice of structuring web content so generative AI systems — including answer engines, AI search, and chat assistants — discover, trust, and cite it when generating responses.
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llms.txt
llms.txt is a plain-text file at the root of a website (https://yourdomain.com/llms.txt) that lists the key pages and content an AI language model should read to understand the site.
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AI Buyer Simulation
AI Buyer Simulation is the practice of running real buyer-intent queries through multiple AI search engines simultaneously and measuring how often a brand is cited, where it ranks, and how it is described — to quantify AI visibility for a domain.
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Share of Voice (AI search)
Share of Voice in AI search is the percentage of buyer-intent queries — across one or more AI engines — in which a given brand is cited, divided by the total of all branded and competing citations.
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AI Overviews
AI Overviews is the Google Search feature that generates a synthesised AI answer at the top of the results page, citing 3–10 web sources beneath the summary.
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Citation Rate
Citation Rate is the percentage of buyer-intent queries in which an AI search engine cites a given domain in its answer, calculated per engine or aggregated across engines.
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BLUF (Bottom Line Up Front)
BLUF — Bottom Line Up Front — is a content structure where the page or section leads with the conclusion or direct answer in the first 1–2 sentences, before any context or buildup.
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E-E-A-T (Experience, Expertise, Authoritativeness, Trustworthiness)
E-E-A-T is Google's framework — Experience, Expertise, Authoritativeness, Trustworthiness — for evaluating content quality, now a top-weighted signal in AI Overviews and Gemini citation choices.
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Model Context Protocol (MCP)
Model Context Protocol (MCP) is an open standard introduced by Anthropic in late 2024 that defines how AI assistants connect to external data sources and tools via a standardised server interface.
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Entity Density
Entity Density is the number of named entities (products, technologies, companies, concepts) per 100 words of content — a structural signal AI engines weight heavily when matching pages to category queries.
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AI crawler
An AI crawler is an automated user-agent operated by an AI company (OpenAI, Anthropic, Perplexity, Google, Meta, ByteDance) that fetches web pages either to train models or to retrieve real-time content for answer generation.
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