GEO & AEO Glossary
Clear, citable definitions of the terms that matter for AI visibility. Each definition is written answer-first so AI engines can extract it directly. For deeper guides, see the blog.
Generative Engine Optimization (GEO)
Generative Engine Optimization (GEO) is the practice of structuring a brand's content, technical infrastructure, and off-site presence so that generative AI platforms, including ChatGPT, Claude, Perplexity, Gemini, and Google AI Overviews, cite the brand as an authoritative source in their responses. GEO targets citation-worthiness rather than keyword ranking.
Read: What is GEO?Answer Engine Optimization (AEO)
Answer Engine Optimization (AEO) is the on-site discipline of formatting content so AI engines can extract a clean, attributable answer from a page and use it in a generated response. Core mechanics include 40-60 word answer blocks placed under question-format headings, FAQPage schema, declarative entity statements, and statistics paired with a source and year.
Read: What is AEO?AI Citation
An AI citation is a direct reference, either a named brand mention or a linked URL, that appears inside an AI-generated response. AI citations carry implicit endorsement because the engine is presenting the brand as a trusted source.
llms.txt
llms.txt is a plain-text file placed at the root of a website that provides AI crawlers with a structured, authoritative description of the brand, its services, and its content. Engines with live web access read it as the most authoritative self-description of a brand.
Read: What is llms.txt?Entity Optimization
Entity optimization is the process of making a brand unambiguous to AI engines by ensuring consistent, factual signals (name, address, phone, category, and relationships) across all owned and third-party sources, so engines can confidently classify and cite the brand.
Prompt Space
The prompt space is the universe of questions potential customers ask AI engines when researching products or services in a given category. Mapping the prompt space identifies which queries drive the business and where competitors are cited instead of you.
Citation Rate
Citation rate is the percentage of tracked prompts that return a citation for a brand across the AI platforms being measured. It is one of the four core dimensions of AI visibility measurement.
Retrieval-Augmented Generation (RAG)
Retrieval-Augmented Generation (RAG) is the architecture used by Perplexity, ChatGPT in web mode, and Google AI Overviews to retrieve live web content before generating an answer. Brands with optimized on-site content benefit most rapidly from RAG-based platforms.
AI Overviews
AI Overviews are Google's AI-generated answer summaries shown above traditional search results. They synthesize and cite multiple sources, making citation inside an AI Overview a high-value visibility outcome.
Answer-First Content
Answer-first content states the direct answer in the first sentence of a section, then adds supporting detail. It uses question-style headings and concise 40-60 word answers, matching how AI engines extract responses and increasing the chance the content is cited.
Read: How AI engines decide what to citeAI Visibility
AI visibility is how often, and how prominently, a brand is cited across AI-generated answers. It is measured across four dimensions: citation rate, AI Share of Voice, average citation position, and AI-referred traffic.
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