AI SEO and GEO glossary

This glossary defines the core AI SEO and GEO terms in one place, each in a single self-contained sentence so the meaning is clear on its own.

Last updated: 18 May 2026

Terms

AEO

Answer Engine Optimization: optimising for direct-answer surfaces such as featured snippets and voice answers. It is related to GEO and AIO but not a strict synonym; see GEO vs AEO vs SEO.

AI Overviews

Google AI Overviews are AI-generated summaries shown above traditional results for some queries, often citing and linking the pages they draw from. See the AI Overviews playbook.

AIO

AI Optimization: the loosest of the AI labels, often used for Google AI Overviews optimization specifically. It overlaps heavily with GEO and AEO and is used loosely.

Answer engine

A system that returns a direct answer to a question rather than a list of links, such as a featured snippet, a voice assistant or an AI assistant.

Answer-shape

Writing so that a single self-contained sentence answers a single question without back-references, which makes it easy for a machine to lift and quote.

Canonical

A link tag that names the preferred URL for a page so that duplicate or parameter variants do not split ranking and citation signals.

Citability

How safely an AI assistant can quote a page, driven by clear authorship, a visible date, a named publisher and outbound links to authoritative sources.

ClaudeBot

Anthropic's crawler user-agent, one of the AI agents a site can allow or block in robots.txt. See the AI crawlers list.

Core Web Vitals

Google's user-experience metrics. The three current ones are Largest Contentful Paint (LCP, loading), Interaction to Next Paint (INP, responsiveness, which replaced First Input Delay in March 2024) and Cumulative Layout Shift (CLS, visual stability).

Crawlability

Whether a crawler is allowed and technically able to fetch a page, which is the prerequisite for being indexed by search or cited by AI.

GEO

Generative Engine Optimization: the practice of making content likely to be cited inside answers generated by AI assistants such as ChatGPT, Claude, Perplexity and Google AI Overviews. See what is GEO.

GPTBot

OpenAI's crawler user-agent, one of the AI agents a site can allow or block in robots.txt. See the AI crawlers list.

JSON-LD

A JSON-based syntax for embedding Schema.org structured data in a page so that machines can read its meaning unambiguously.

llms.txt

A plain-text file at a site root intended to point AI assistants to the most important content; an emerging convention, not an adopted web standard. See what llms.txt is.

PerplexityBot

Perplexity's crawler user-agent, one of the AI agents a site can allow or block in robots.txt. See the AI crawlers list.

Raw HTML

The HTML a server returns before any client-side JavaScript runs; this is what most major AI crawlers read, since they do not reliably execute JavaScript.

robots.txt

A root file following the Robots Exclusion Protocol that tells crawlers which paths and user-agents may or may not fetch a site.

Schema.org

A shared vocabulary of types and properties, usually expressed as JSON-LD, used to describe page content to machines.

SEO

Search Engine Optimization: optimising a site so it ranks in classic search engine result links; the foundation the AI disciplines build on.

Sitemap

An XML file listing a site's URLs so that crawlers can discover them, usually referenced from robots.txt.

Structured data

Machine-readable metadata describing a page's content and entities, most commonly Schema.org expressed as JSON-LD.

Training opt-out

A robots.txt token such as Google-Extended or Applebot-Extended that signals content should not be used for AI training; it does not block crawling.

User-agent

The name a crawler identifies itself with in its requests and in robots.txt rules, for example GPTBot or PerplexityBot.

Published by XEOscan, a free tool operated by Constantin Ungureanu.