Plain-English definitions of every AEO, GEO, and AI visibility term — from citation rate to llms.txt. Each definition is grounded in real tracking data from Visiby's prompt dataset, not theory.
The landscape of search is undergoing its most radical transformation since the invention of the blue link. Generative AI engines—like ChatGPT, Perplexity, and Google's AI Overviews—are fundamentally changing how consumers discover products, research brands, and make purchasing decisions. Instead of scrolling through ten organic search results, users now expect direct, synthesized answers delivered in a conversational format.
This paradigm shift brings an entirely new lexicon for digital marketers, founders, and SEO professionals. Terms that didn't exist a year ago are now boardroom priorities. Traditional metrics like "keyword ranking" and "search volume" are being rapidly supplemented—and in some cases replaced—by concepts like "citation rate," "generative engine optimization (GEO)," and "AI share of voice."
We created this AI Search Glossary to cut through the noise and provide clear, authoritative definitions for the AEO, GEO, and AI visibility terms you need to know. Unlike speculative SEO blogs, every definition in this glossary is grounded in actual tracking data. At Visiby, our platform processes millions of data points across thousands of commercial prompts weekly (Source: Visiby internal data, June 2026), allowing us to see exactly how these engines operate in the wild.
Whether you are an agency educating clients on why their traffic is dropping, an in-house marketer pivoting to an answer-engine strategy, or a founder trying to understand how to get ChatGPT to recommend your software, this glossary serves as your foundational reference guide. Bookmark this page, as we update it weekly with new terminology as the AI search ecosystem evolves.
How often AI engines like ChatGPT cite or recommend your brand. The core metric that replaces keyword rankings for AI search.
Read AI Visibility definition →02The practice of getting your brand chosen as the answer in AI search results, featured snippets, and voice replies.
Read AEO (Answer Engine Optimization) definition →03The percentage of AI answers that cite your brand for a set of tracked prompts. The fundamental metric of AI visibility.
Read Citation Rate definition →04Your brand's citation frequency versus competitors in AI-generated answers. Measures category dominance in the AI-answer era.
Read AI Share of Voice definition →05A plain-text Markdown file served at your domain root that helps LLM crawlers digest site structure and prioritize core content.
Read llms.txt definition →06Google's AI-generated answer panels shown at the top of search results, synthesizing information from multiple sources.
Read AI Overviews definition →07The percentage of prompts for which your brand is simultaneously cited across two or more independent AI answer engines.
Read Citation Overlap definition →08Structuring content around clearly defined entities (brands, people, products) to build Knowledge Graph authority.
Read Entity SEO definition →09Automated web bots (GPTBot, PerplexityBot, ClaudeBot) used to fetch web content for LLM training or live RAG retrieval.
Read AI Crawler definition →10Search sessions where user intent is fully satisfied directly within the AI or SERP interface without clicking an external link.
Read Zero-Click Search definition →11Your brand's total AI citations measured as a percentage of all brand citations awarded across your competitive market category.
Read Share of Citations definition →Shaping content so that generative AI engines cite, mention, or recommend your brand inside synthesized answers.
Coming soonGoogle's conversational AI search interface that provides detailed, multi-turn answers powered by Gemini.
Coming soonA curated set of real buyer questions used to sample AI engines and measure brand citation rates over time.
Coming soonA prioritized action plan identifying the exact pages and passages to update to improve AI citation rates.
Coming soonStructuring content around clearly defined entities (brands, people, products) so AI engines can identify and cite them.
Coming soonTracking which AI crawlers (GPTBot, PerplexityBot, etc.) visit your site, how often, and which pages they prioritize.
Coming soonA search system that returns a synthesized answer instead of a list of links. ChatGPT, Perplexity, and Google AI Overviews are answer engines.
Coming soonAn AI system that generates original text responses by synthesizing information from multiple retrieved sources.
Coming soonHow do we know how these algorithms work? The truth is that generative models do not publish their ranking factors or index weights. The only way to truly understand AI visibility is through rigorous, experiential testing at scale.
Our methodology involves curating massive prompt libraries containing the exact high-intent questions real buyers ask. We systematically run these queries across ChatGPT (GPT-4), Perplexity (Pro and Standard), and Google's Gemini-powered AI Overviews. By extracting the synthesized answers and mapping the citations back to the source domains, we reverse-engineer the visibility landscape.
This empirical approach ensures that our definitions for AEO, GEO, and AI visibility aren't just theoretical jargon—they are practical, measurable concepts that drive real revenue. When we define a "Fix Brief," it is because we actively generate thousands of them for our enterprise clients, pinpointing the exact semantic gaps they need to close to win back their market share from competitors.
Drop your domain. We'll run a live AI visibility sweep across ChatGPT, Perplexity, and Google AI Overviews — and send your team the first report.