// glossary
Glossary
Plain-English definitions for the terms that matter in AI search and SEO.
AI answer engine
An AI answer engine is a tool that responds to queries with a generated, direct answer rather than a list of links, including ChatGPT, Perplexity, and Google AI Overviews.
Read definition →AI Mode
Google's conversational AI search experience. Like AI Overviews, it grounds answers in indexed content, so staying indexable and helpful is the way in.
Read definition →AI Overviews
Google's AI-generated answer that can sit above the organic links. Here is where it comes from, how your site gets pulled in, and why it is still SEO.
Read definition →Answer Engine Optimization (AEO)
AEO is the practice of making a site readable by AI answer engines like ChatGPT, Perplexity, and Google AI Overviews, built on top of standard SEO fundamentals.
Read definition →Canonical URL
The page version you want Google to treat as the original among duplicates, declared with rel=canonical so ranking signals consolidate to one address.
Read definition →ClaudeBot
Anthropic's training crawler for Claude. You can opt out of model training with ClaudeBot while still allowing Claude-SearchBot to fetch you for answers.
Read definition →Core Web Vitals
Google's three page-experience metrics: LCP for loading, INP for interactivity, and CLS for visual stability. What each one measures and why it matters.
Read definition →Crawlability
Crawlability is whether search and AI crawlers can reach and fetch your pages and the CSS and JavaScript they need. Block those resources and you lose ranking.
Read definition →E-E-A-T
Experience, Expertise, Authoritativeness, Trustworthiness: the framework Google uses to describe good content. Trust matters most, and it is not a ranking dial.
Read definition →Generative Engine Optimization (GEO)
GEO is a common synonym for answer engine optimization. For Google it is just SEO. A useful label, not a separate playbook. Here is what it actually means.
Read definition →Google-Extended
A robots.txt token controlling whether Google uses your content to train and ground Gemini. It does not control AI Overviews, which use the Search index.
Read definition →Googlebot
Googlebot is Google's web crawler. It comes in two flavours, reads the first 2MB of a page, and works mostly mobile-first. Here is what that means for you.
Read definition →GPTBot
GPTBot is OpenAI's crawler that collects web content to train its models. It respects robots.txt, and it is not the bot that powers ChatGPT search results.
Read definition →Indexing
Indexing is when Google stores a crawled page in its index so it can be served in results. Here is what that means and how to check whether your pages made it.
Read definition →Legibility Score
Rankport's Legibility Score is a 0-100 metric that measures how readable a site is to both search engines and AI answer engines, across four sub-scores.
Read definition →llms.txt
llms.txt is an unofficial plain-text file at a site's root meant to describe it to AI crawlers. There is little evidence AI systems actually use it.
Read definition →Mobile-first indexing
Google primarily indexes the mobile version of your site with Googlebot Smartphone. Here is what that means in practice, and how to avoid getting caught out.
Read definition →OAI-SearchBot
OAI-SearchBot is OpenAI's crawler that powers ChatGPT's search results. Allow it to be eligible to appear in ChatGPT's answers. It respects robots.txt.
Read definition →PerplexityBot
PerplexityBot is Perplexity's indexing crawler. It reads raw HTML, ignores JavaScript, and respects robots.txt. Here is what it does and why it matters.
Read definition →Query Fan-Out
How Google's AI features break one search into several related sub-queries, fire them at once, and gather sources from the index to build a single answer.
Read definition →Rendering (client vs server)
Rendering is how your code becomes the final HTML a crawler reads. Where it happens, in the browser or on the server, decides what search engines can see.
Read definition →Retrieval-Augmented Generation (RAG)
RAG is the technique that lets an AI model fetch real documents and ground its answer in them. It is how Google's AI Overviews stay anchored to the web.
Read definition →robots.txt
A root file telling crawlers what they may fetch. It controls crawling, not indexing — that needs a noindex tag. Here is the difference and why it matters.
Read definition →Structured data (Schema.org)
Machine-readable markup that describes your page to search engines and can make it eligible for rich results. Helpful for SEO, never an AI requirement.
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