Glossary · 31 terms

The language of AI visibility.

GEO, spread, grounding, the weekly close — the vocabulary of a discipline that didn’t exist three years ago, defined in plain English. Each term links to where you can see the concept in the live index.

AI CrawlerAn AI crawler is a bot that fetches web content for AI systems — for training corpora (GPTBot, ClaudeBot), or for live retrieval when a user's question triggers a search (PerplexityBot, OAI-SearchBot).
AI OverviewsAI Overviews are Google Search's AI-generated answer blocks that appear above the organic results, synthesizing an answer with citations before any traditional listing is seen.
AI VisibilityAI visibility is how often, how early, and how favorably AI assistants like ChatGPT, Claude, Gemini, and Perplexity name a brand when people ask them for recommendations.
AI Visibility ScoreAn AI Visibility Score is a 0–100 measure of how prominently a single AI model recommends a brand in a category, based on whether the brand is mentioned, how early it appears, and how consistently it shows up across queries.
Answer EngineAn answer engine is a system that responds to a query with a direct, synthesized answer instead of a list of links — Perplexity, ChatGPT with browsing, and Google's AI Overviews are the canonical examples.
Answer Engine Optimization (AEO)AEO is optimizing content so answer engines — AI systems that reply with a direct answer instead of a list of links — surface and cite your brand.
Brand MentionA brand mention is any time an AI answer names a brand — the atomic unit of AI visibility, from which ranks, scores, and share of voice are computed.
CitationA citation is a source link an AI answer attaches to a claim — the page the model retrieved and leaned on when composing its response.
Consensus RankA consensus rank is a brand's blended position across all tracked AI models — the single number that summarizes where the market of models places the brand.
EntityAn entity is a distinct thing — a brand, product, person, or place — that machines can identify and connect facts to. Strong entity recognition is a precondition for being recommended by AI.
Gainers & LosersGainers and losers are the brands with the largest upward and downward rank movement at a weekly close — the movers board of an AI visibility index.
Generative Engine Optimization (GEO)GEO is the practice of improving how often and how favorably generative AI engines — ChatGPT, Claude, Gemini, Perplexity — recommend a brand in their answers. It is the AI-era counterpart to SEO.
GroundingGrounding is when an AI model bases its answer on retrieved, verifiable sources — live web results or documents — instead of relying only on what it learned in training.
HallucinationA hallucination is an AI answer stated confidently but not supported by the model's training data or retrieved sources — including invented products, wrong prices, and misattributed features.
Knowledge CutoffA knowledge cutoff is the date after which a model's training data ends — without retrieval, the model's picture of a market is frozen at that date.
LLM Optimization (LLMO)LLMO is a synonym for GEO: the discipline of improving a brand's presence in large language model outputs, from training data through retrieved sources.
llms.txtllms.txt is a proposed convention: a markdown file at a site's root that gives AI systems a concise, curated map of the site's most important content — robots.txt tells crawlers where they may go; llms.txt tells models what matters.
Model ColumnA model column is one AI model's independent ranking of a category, displayed side by side with the other models' — the format that makes cross-model disagreement visible.
Most ContestedA most-contested ranking is a category where AI models disagree the most — different models crown different #1 brands, or brands carry wide spreads between their best and worst model ranks.
MovementMovement is a brand's week-over-week rank change on an AI visibility index — up, down, unchanged, new entry, or re-entry — the AI-ranking equivalent of a price change on a ticker.
Prompt TrackingPrompt tracking is monitoring a fixed set of buying questions across AI models on a schedule, recording every answer, and measuring how a brand's presence in those answers changes over time.
ReceiptsReceipts are the stored raw model answers behind an AI visibility score — the verifiable evidence that a reported rank reflects what a model actually said.
Recommendation QueryA recommendation query is a question that asks an AI to name specific products, brands, or places — "best X for Y" — the query class where AI visibility is won or lost.
Retrieval-Augmented Generation (RAG)RAG is the architecture where a model retrieves relevant documents first and generates its answer from them — the mechanism behind grounded, citation-backed AI answers.
SentimentIn AI visibility, sentiment is how favorably an answer frames a brand when it mentions it — recommended, neutral, caveated, or warned against.
Share of VoiceIn AI visibility, share of voice is the percentage of relevant AI answers that mention a brand, across a defined set of prompts, models, and time.
SpreadSpread is the gap between a brand's best and worst rank across AI models — the disagreement signal. A spread of 0 means every model agrees; a wide spread means the models see the brand very differently.
Structured Data (Schema.org)Structured data is machine-readable markup (JSON-LD using Schema.org vocabulary) embedded in web pages that states facts explicitly — what a product is, what it costs, how it's rated — so crawlers and AI systems don't have to infer them.
The AI 100The AI 100 is WhereDoIRank's name for the flagship cross-category board: the brands with the strongest overall AI visibility across every tracked category, ranked like an index of listed companies.
Weekly CloseThe weekly close is the moment an AI visibility index locks in the week's rankings — the fixed reference point that all movement is measured against.
Zero-Click SearchA zero-click search is a query resolved entirely on the results page or inside an AI answer — the user gets what they need without visiting any website.