Glossary
Plain definitions of the terms used in SEO and AI search, from AI Overviews to robots.txt. Each one states its source and links the tool that checks it.
27 terms. Definitions are written to be quoted on their own; where a vendor documents the behaviour, the source is linked on the term's page.
Access
Can crawlers reach and render every key page?
- Canonical URL
- A canonical URL is the single address a site declares as the authoritative version of a page when the same content is reachable at several URLs, usually with a rel=canonical link element.
- ClaudeBot
- ClaudeBot is Anthropic's crawler for collecting web content that may be used to train Claude models; Anthropic documents separate agents, Claude-SearchBot and Claude-User, for search and user fetches.
- Content Signals
- Content Signals is a draft convention for stating in robots.txt how a site's content may be used, with three signals: search, ai-input (use in generated answers) and ai-train (model training).
- Core Web Vitals
- Core Web Vitals are three user-experience metrics Google reports for real page loads: Largest Contentful Paint (loading), Interaction to Next Paint (responsiveness) and Cumulative Layout Shift (visual stability).
- Crawl budget
- Crawl budget is the number of URLs a search engine's crawler is willing and able to fetch from a site in a period, set by the site's server capacity and the crawler's demand for its pages.
- Google-Extended
- Google-Extended is a robots.txt control token, not a crawler: it tells Google whether a site's content may be used to train Gemini models, without affecting Googlebot or appearance in Search.
- GPTBot
- GPTBot is OpenAI's web crawler for collecting content that may be used to train its models; it identifies itself in the user agent and honours robots.txt.
- llms.txt
- llms.txt is a proposed plain-text file at a site's root that summarises the site and links its key pages in Markdown, intended for large language models rather than people.
- OAI-SearchBot
- OAI-SearchBot is the OpenAI crawler that builds the index used by ChatGPT search; blocking it in robots.txt removes a site from those results, while GPTBot controls training use.
- PerplexityBot
- PerplexityBot is the crawler that builds Perplexity's search index; Perplexity also documents Perplexity-User, which fetches a page when a user's question needs it and is not bound by robots.txt in the same way.
- Rendering (JavaScript SEO)
- Rendering is the step in which a crawler executes a page's JavaScript to build the final content; Googlebot renders pages in a second pass, and the documented AI crawlers do not describe a rendering step.
- robots.txt
- robots.txt is a plain-text file at a site's root that tells crawlers which paths they may or may not fetch, using User-agent, Allow and Disallow rules; it controls crawling, not indexing.
Understand
Do machines know what each page and brand is?
- Entity
- An entity is a thing that search engines and AI systems can identify unambiguously, such as a company, a person, a product or a place, independent of the words used to name it.
- Entity SEO
- Entity SEO is the work of making an organization, its founder and its services unambiguous to search engines and AI systems: one name, one description and one set of facts, repeated identically on the site, on profiles and in structured data.
- Knowledge Graph
- The Knowledge Graph is Google's database of entities and the relationships between them, which powers knowledge panels and helps Search and AI features understand what a page is about.
- sameAs
- sameAs is a schema.org property that links a structured-data node to other pages that are about the same entity, such as a company's LinkedIn page or a founder's profile.
- Structured data (JSON-LD)
- Structured data is machine-readable markup, usually JSON-LD using the schema.org vocabulary, that states what a page is about so search engines and AI systems can read its facts without guessing.
Retrieve
Can a passage be lifted as a clear answer?
- AI Mode
- AI Mode is Google's conversational search experience: a full-page generated answer that can run several searches behind one question and cites web pages as sources.
- Answer engine optimization (AEO)
- Answer engine optimization (AEO) is the practice of researching the questions buyers ask and building pages that answer each one first, specifically and with a source, so featured snippets, AI Overviews and assistants can lift a clear, correct answer.
- Answer-first passage
- An answer-first passage is a self-contained block of text that states the answer to a question in its first sentence, then the specifics and the source, so a search engine or assistant can quote it on its own.
Cite
Are you mentioned and cited, accurately?
- AI Overviews
- AI Overviews are the AI-generated summaries Google shows at the top of some search results, with links to the pages the summary draws on.
- AI search optimization
- AI search optimization is the work of making a company findable and accurately described in AI-generated answers, from Google's AI Overviews and AI Mode to ChatGPT search, Perplexity, Copilot and Gemini.
- Citation rate
- Citation rate is the share of sampled AI answers in which a site is linked as a source, measured on a fixed prompt set, per engine, over several runs, and reported with its spread.
- Crawl-to-Citation Method
- The Crawl-to-Citation Method is AISEOExpert.co's six-stage framework for SEO and AI search, Access, Understand, Trust, Retrieve, Cite and Convert, each with a deliverable and a measure.
- Generative AI performance report (Search Console)
- The Generative AI performance report in Google Search Console counts how many times links to a site were shown in AI Overviews and AI Mode, by page, country, device and date. It reports impressions, not clicks.
- Generative engine optimization (GEO)
- Generative engine optimization (GEO) is the practice of making content usable and citable by systems that generate answers rather than list links: clear claims, sources, visible dates and authors, and original data.
- Mention rate
- Mention rate is the share of sampled AI answers in which a company is named, whether or not a page is linked; it is measured on a fixed prompt set, per engine, with the spread across runs shown.