AI Visibility Glossary
Plain-English definitions for GEO, AI search, citation metrics, and the signals that affect how brands appear in ChatGPT, Perplexity, Gemini, Claude, and Google AI results.
Core Concepts
Agentic Browsing
The capability of AI agents to autonomously navigate websites, interact with pages, and retrieve information in real time — without a human directing each step.
AI Search Optimization
The broader practice of optimizing digital presence across all AI search surfaces, including ChatGPT, Perplexity, Google AI Overviews, and voice assistants.
Answer Engine Optimization (AEO)
An earlier term for optimizing content to appear in AI-generated answers, now largely synonymous with GEO.
Generative Engine Optimization (GEO)
The practice of optimizing web content so that AI search engines (ChatGPT, Perplexity, Claude, Gemini) cite or recommend it when answering user questions.
Query Fan-out
The process by which an AI search engine decomposes a single user query into multiple sub-queries, retrieving information from several sources to construct a more comprehensive answer.
Retrieval-Augmented Generation (RAG)
An AI architecture where a model retrieves relevant documents from the web or a database before generating an answer, grounding responses in current sources.
Zero-Click Search
A search session where the user gets their answer directly from the results page (AI Overview, featured snippet, knowledge panel) without clicking through to any website.
Platforms
AI Search
Search experiences powered by large language models that return conversational answers rather than ranked lists of links.
ChatGPT Search
OpenAI's web search feature inside ChatGPT, which retrieves live web content and synthesizes answers with source citations.
Google AI Mode
Google's dedicated AI search interface, launched May 2025, that delivers multi-turn conversational answers alongside traditional search results using Gemini models.
Google AI Overviews
AI-generated summaries that appear at the top of Google search results, synthesizing content from multiple web pages before the organic link list.
Perplexity
An AI-native search engine that answers questions with cited sources, built around retrieval-augmented generation rather than a traditional link index.
Metrics
Citation Rate
The percentage of relevant AI search queries for which a brand is mentioned or cited in the AI-generated answer.
Citation Share
The fraction of citations within a specific query or topic where your brand is the cited source, as opposed to a competitor.
Competitive Citation Gap
The queries where a competitor is cited in AI answers but your brand is not — representing the highest-priority opportunities for AI visibility improvement.
Query Coverage
The breadth of queries for which a brand appears in AI answers — how many distinct user questions trigger a citation, rather than how often any single query cites you.
Share of Voice (AI)
The proportion of AI-generated answers in your category that mention your brand, compared to all brands mentioned across the same query set.
Visibility Drift
The gradual decline in AI citation rate over time as AI platforms update their indexes, competitors improve, or content becomes stale — without any active change on your part.
Content Signals
E-E-A-T
Google's quality evaluation framework — Experience, Expertise, Authoritativeness, and Trustworthiness — used by quality raters to assess content credibility, and increasingly relevant to how AI systems evaluate sources.
llms.txt
A plain-text file at the root of a website that provides AI systems with a structured summary of the brand, products, and preferred citations — analogous to robots.txt but for LLMs.
Product Schema
Schema.org structured data that marks up a product page with machine-readable attributes including name, price, availability, brand, and reviews.
Schema.org Markup
Structured data vocabulary (JSON-LD, Microdata, or RDFa) added to web pages to help search engines and AI systems understand page content as machine-readable entities.
Operations
AI Crawlers
Specialised web crawlers operated by AI platforms — including GPTBot (OpenAI), ClaudeBot (Anthropic), Google-Extended, and PerplexityBot — that index web content for LLM training and AI search.
AI Search Audit
A systematic analysis of a brand's current visibility in AI-generated answers, identifying citation rate, competitive gaps, technical barriers, and prioritized fixes.
Citation Testing
The practice of systematically querying AI search platforms to measure whether and how a brand is cited in AI-generated answers.
Want to know how your brand appears in AI answers?
Run an AnswerAtlas AI Visibility Audit and see how AI assistants like ChatGPT, Gemini, and Claude describe, cite, and recommend your brand — and whether competitors appear instead.