GEO & SEO Glossary

Plain-language definitions of the terms behind AI search optimization.

28 terms

GEO & AI search

7 terms
GEO (Generative Engine Optimization)
Generative Engine Optimization (GEO) is the practice of structuring and writing web content so AI engines like ChatGPT, Google AI Overviews, and Perplexity cite, quote, and surface it in generated answers.Read the guide
AEO (Answer Engine Optimization)
Answer Engine Optimization (AEO) is the practice of optimizing content to be selected as the direct answer by answer engines and AI assistants, focusing on concise, factual, question-led phrasing that machines can extract cleanly.Read the guide
Answer engine
An answer engine is a search system that delivers direct, synthesized answers to queries rather than a list of links, using AI to summarize and cite sources, as seen in Perplexity and Google AI Overviews.
AI Overviews
AI Overviews are Google’s AI-generated summaries shown at the top of search results, synthesizing information from multiple web sources to answer a query directly and often citing the pages they draw from.
Knowledge graph
A knowledge graph is a structured network of entities and the relationships between them that search engines and AI systems use to understand context, connect facts, and deliver accurate, entity-based answers.

AI & language models

5 terms
LLM (Large Language Model)
A Large Language Model (LLM) is an AI system trained on vast text datasets to understand and generate human-like language, powering tools like ChatGPT, Claude, and Gemini for tasks such as answering questions and summarizing content.
RAG (Retrieval-Augmented Generation)
Retrieval-Augmented Generation (RAG) is an AI technique that retrieves relevant documents from an external source at query time and feeds them to a language model, producing more accurate, current, and citable answers.
Embeddings
Embeddings are numerical vector representations of text that capture semantic meaning, allowing AI systems to measure similarity and retrieve the most relevant content for search, recommendations, and retrieval-augmented generation.
Hallucination
A hallucination is when an AI language model generates information that is false, fabricated, or unsupported by its sources, presenting it confidently as fact. Grounding content in reliable data helps reduce hallucinations.
Grounding
Grounding is the practice of anchoring an AI model’s responses to verified external sources or retrieved data, improving factual accuracy and enabling citations while reducing hallucinations in generated answers.

Content & markup

8 terms
E-E-A-T
E-E-A-T stands for Experience, Expertise, Authoritativeness, and Trustworthiness, the quality signals Google and AI engines use to assess content credibility and decide which pages to rank, cite, and surface in answers.
Machine readability
Machine readability is how easily software, crawlers, and AI engines can parse and understand a webpage’s content and structure, achieved through clean HTML, structured data, and clear semantic markup.
Semantic HTML
Semantic HTML uses meaningful tags like <article>, <header>, <nav>, and <section> to convey the structure and purpose of content, helping browsers, search engines, and AI engines accurately interpret a page.
Structured data
Structured data is standardized, machine-readable markup added to a webpage that describes its content explicitly, helping search engines and AI engines understand entities, generate rich results, and surface accurate information.
JSON-LD
JSON-LD (JavaScript Object Notation for Linked Data) is Google’s preferred format for adding structured data to a page, embedding Schema.org markup in a script tag to describe content for search engines and AI engines.
Schema.org
Schema.org is a shared vocabulary of structured data types and properties, created by Google, Microsoft, Yahoo, and Yandex, that lets websites describe content in a standardized way machines and AI engines understand.
Rich results
Rich results are enhanced search listings, such as star ratings, FAQs, recipes, and event details, generated from structured data that make a page more visible and informative directly in search results.
SSR (Server-Side Rendering)
Server-Side Rendering (SSR) generates a page’s full HTML on the server before sending it to the browser, ensuring crawlers and AI engines can read all content immediately without executing JavaScript.

Crawlers & access

8 terms
robots.txt
robots.txt is a text file at a website’s root that tells web crawlers and AI bots which pages or sections they may or may not access, controlling crawling behavior and AI training data collection.Read the guide
llms.txt
llms.txt is a proposed plain-text Markdown file placed at a site’s root that guides AI engines to the most important, well-structured content, helping large language models understand and cite a site accurately.Read the guide
Web crawler
A web crawler is an automated bot that systematically browses and downloads web pages to index them for search engines or collect data for AI training, following links and respecting robots.txt rules.
GPTBot
GPTBot is OpenAI’s web crawler that collects publicly available content to train ChatGPT and its models. Site owners can allow or block it in robots.txt to control whether their content is used.Read the guide
PerplexityBot
PerplexityBot is the web crawler used by Perplexity AI to index web pages so they can be retrieved, summarized, and cited in its answer engine’s real-time, source-backed responses.Read the guide
Google-Extended
Google-Extended is a robots.txt control token that lets site owners decide whether their content can be used to train Google’s Gemini models and improve AI features, without affecting normal Search indexing.Read the guide
XML sitemap
An XML sitemap is a structured file listing a website’s important URLs, helping search engine crawlers and AI engines discover, prioritize, and index pages efficiently, especially on large or newly published sites.
Canonical URL
A canonical URL is the preferred version of a page specified with a rel=canonical tag, telling search engines which URL to index when duplicate or similar content exists across multiple addresses.