Glossary
AEO & GEO Glossary: Every Term Explained in Plain English
This glossary defines every term commonly used in AI Search Optimization (AEO/GEO), in one plain sentence each, in the order a beginner would want to encounter them. Every definition below is also published as structured data (schema.org DefinedTerm), so it can be read directly by AI systems as well as people.
Answer Engine Optimization (AEO)
The practice of structuring a business's content, data, and technical signals so that AI systems such as ChatGPT, Perplexity, Gemini, and Google AI Overview cite and recommend that business directly inside an answer, instead of only ranking a link in traditional search results.
Generative Engine Optimization (GEO)
A term used interchangeably with AEO. The industry hasn't settled on a single name for this discipline yet; some use AEO, some use GEO, and both describe the same underlying work.
Answer Engine
A search tool, such as ChatGPT, Perplexity, or Google AI Overview, that responds to a question with a direct, generated answer instead of a list of links to click through.
Citation Frequency
How often a business is named or quoted by an AI model when a customer asks a relevant question. This is the core metric AEO work is trying to move.
Live Retrieval
The process by which an AI model searches the current web in real time to answer a question, the way ChatGPT with browsing enabled, Perplexity, and Google AI Overview typically operate.
Parametric Knowledge
Information an AI model learned during training and stores internally, used when it answers without searching the live web. Much slower and harder for a business to influence than live retrieval.
Query Fan-Out
The pattern where an AI model breaks one user question into several smaller sub-questions and retrieves an answer for each separately, which is why many narrow, specific answers usually outperform one broad page.
Schema Markup
Structured data, usually written as JSON-LD, added to a webpage to explicitly label what the page is about in a format machines can read directly, instead of leaving a model to infer it from prose.
llms.txt
An emerging, informal standard: a plain-text file published at a website's root that summarizes the business in a format built to be read and quoted directly by AI crawlers.
AI Crawler Allow-Listing
Explicitly permitting AI-specific crawlers, such as GPTBot, PerplexityBot, and ClaudeBot, to access a site through its robots.txt file, since some AI systems treat an unlisted site as opted out entirely.
Outside Corroboration
Mentions of a business on third-party sites, such as reviews, directories, and news coverage, which AI models generally weigh more heavily than claims a business makes about itself on its own website.
Direct-Answer Content
Content written to answer a specific question completely within the first few sentences, rather than building up to the answer, matching how AI models score passages for relevance.
Retrieval-Augmented Generation (RAG)
A technique where an AI model retrieves relevant documents or passages from an external source before generating an answer. This is the underlying mechanism behind most live-retrieval AI search tools.
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