AI Visibility Glossary
Plain-English definitions of the terms behind AI search — how AI engines decide which brands to cite, recommend, and name in their answers.
AI Visibility
AI visibility is how often and how prominently a brand appears in the answers generated by AI engines like ChatGPT, Gemini, Claude, and Perplexity. A brand with high AI visibility is named, cited, and recommended when people ask AI for options in its category.
AEO (Answer Engine Optimization)
AEO, or Answer Engine Optimization, is the practice of optimizing content and brand signals so AI answer engines surface and recommend you in their responses. Where SEO targets a ranked list of links, AEO targets being the answer itself.
GEO (Generative Engine Optimization)
GEO, or Generative Engine Optimization, is the practice of earning citations and mentions inside generative AI responses. It focuses on becoming a source the model trusts and pulls from when it composes an answer, rather than ranking in a traditional index.
SEO (Search Engine Optimization)
SEO, or Search Engine Optimization, is the practice of improving a website's ranking in traditional search results like Google. It optimizes content, technical health, and backlinks to earn clicks from a ranked list of links.
Answer Engine
An answer engine is an AI system that responds to a query with a direct, synthesized answer instead of a list of links. ChatGPT, Perplexity, Google AI Overviews, Gemini, and Copilot are answer engines that pull from web sources to compose responses.
Signal Score
The Signal Score is Top Citation Signal's 0–100 composite measure of a brand's AI visibility. It combines eight weighted signals — citation, trust, entity strength, coverage, source diversity, consistency, freshness, and expert mentions — into one comparable number.
Citation Rate
Citation rate is how frequently AI engines cite a brand or its website as a source when answering questions in its category. A high citation rate means the engine repeatedly leans on your content to ground its answers.
Entity Strength
Entity strength is how clearly AI models recognize a brand as a distinct, well-defined entity — connecting its name, website, products, people, and profiles into one coherent thing. Weak entity strength means AI is unsure what your brand is.
Share of Voice (in AI)
Share of voice in AI is the proportion of AI answers in your category where your brand is named, relative to competitors. It shows how much of the AI conversation you own versus how much your rivals capture.
Knowledge Graph
A knowledge graph is a structured network of entities — brands, people, products, places — and the relationships between them. AI systems use knowledge graphs to understand what a brand is and how it connects to the rest of the world.
Grounding
Grounding is when an AI engine bases its answer on retrieved, real-world sources rather than relying only on its trained memory. Grounded answers cite the pages the model pulled from, often via live web search.
RAG (Retrieval-Augmented Generation)
RAG, or Retrieval-Augmented Generation, is a technique where an AI model retrieves relevant documents and uses them to generate a grounded answer. It's the mechanism behind most answer engines that cite live sources.
llms.txt
llms.txt is a proposed standard file, placed at a site's root, that gives AI engines a clean, markdown summary of what the site is and where its key content lives. It helps models understand and accurately represent a brand.
Trust Signal
A trust signal is evidence AI uses to judge whether a brand is credible — such as citations from authoritative sites, reviews, expert coverage, and consistent third-party mentions. High-trust sources vouching for you raise your standing.
Source Diversity
Source diversity is the range of independent domains and publishers that reference a brand. A brand cited by many different reputable sources is more resilient and credible in AI answers than one cited by only a handful.
Consistency
Consistency is how uniformly a brand is described across AI answers, engines, and sources over time. When your name, category, and positioning are stated the same way everywhere, AI recognizes and trusts you more.
Freshness
Freshness is how recent the citations, mentions, and references about a brand are. AI engines favor current information, so a steady stream of up-to-date coverage keeps a brand relevant in answers.
Expert Mentions
Expert mentions are references to a brand in expert, editorial, or analyst-grade sources — the kind of coverage that carries outsized authority. AI engines weight these heavily when deciding who to trust and recommend.
Hallucination
A hallucination is when an AI engine states something false or fabricated with confidence — for example, giving a brand the wrong pricing, features, or category. Hallucinations about your brand mislead buyers reading the answer.
Zero-Click
Zero-click describes searches and AI queries that are answered on the results page or in the AI response itself, without the user clicking through to a website. The answer is consumed in place.
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