Reference
The AI optimization glossary
Plain-English definitions of the concepts behind GEO, AEO and AIO — and head-to-head comparisons of the ones people confuse most.
// Terms
AI Optimization (AIO)
AI Optimization (AIO) is the practice of structuring your web presence so that AI engines — ChatGPT, Claude, Perplexity, Gemini an…
TermAnswer engine
An answer engine is a system that responds to a query with a direct, synthesized answer rather than a list of links. Examples incl…
TermAI Overview
A Google AI Overview is the AI-generated summary that appears at the top of some search results, synthesizing an answer from multi…
Termllms.txt
llms.txt is a proposed Markdown file placed at a website’s root that describes the site and links to its key resources, helping AI…
TermContent-Signal
Content-Signal is an emerging robots.txt directive that lets a site separate three permissions: search indexing, AI retrieval (RAG…
TermStructured data (JSON-LD)
Structured data is machine-readable markup, usually JSON-LD using the Schema.org vocabulary, that describes a page’s content to en…
TermEntity SEO
Entity SEO is the practice of getting your brand, people or products recognized as distinct, trusted entities across the web and i…
TermLLM citation
An LLM citation is when an AI model names, links or attributes your content as a source in the answer it gives a user. It is disti…
TermModel Context Protocol (MCP)
The Model Context Protocol (MCP) is an open standard that lets AI assistants connect to external tools and data sources through a …
TermRetrieval-augmented generation (RAG)
Retrieval-augmented generation (RAG) is a technique where an AI model fetches relevant external documents at answer time and groun…
TermE-E-A-T
E-E-A-T stands for Experience, Expertise, Authoritativeness and Trustworthiness — the quality framework Google uses to assess cont…
TermAI crawler
An AI crawler is a bot run by an AI company to fetch web content for model training or live retrieval. Examples include GPTBot, Cl…
TermAI visibility (share of voice)
AI visibility is how often and how prominently AI engines — ChatGPT, Claude, Perplexity, Gemini, Google AI Overviews — name your b…
TermAI referral traffic
AI referral traffic is the visits that reach your site when a user clicks a link inside an AI-generated answer — from ChatGPT, Per…
Head-to-head comparisons
GEO vs SEO
GEO optimizes to be cited by generative engines; SEO optimizes to rank and be clicked. A comparison of goals, tactics, metrics and…
CompareAEO vs GEO
AEO and GEO overlap heavily. The useful distinction: GEO optimizes the content engines draw from; AEO optimizes to be the answer i…
CompareAEO vs SEO
SEO targets rankings and clicks; AEO targets being the synthesized AI answer — a distinct discovery layer you can win without rank…
Comparellms.txt vs robots.txt
robots.txt controls whether crawlers may access content; llms.txt describes and links it for AI agents. One is access control, the…
CompareAI Overviews vs Featured Snippets
A featured snippet quotes one source verbatim; an AI Overview synthesizes an answer from several cited sources. How they differ an…
CompareAI Visibility Tracking vs Server Logs
AI visibility trackers sample prompts across engines; server log analysis is a complete census of your domain. One estimates the m…