GEO & AI-Search Glossary

Plain-English definitions of the terms you’ll meet when optimizing for AI search.

GEO (Generative Engine Optimization)

Generative Engine Optimization (GEO) is the practice of improving how a brand or website appears and gets cited in AI-generated answers from engines like ChatGPT, Perplexity and Google AI Overviews — the AI-era counterpart to traditional SEO.

AEO (Answer Engine Optimization)

Answer Engine Optimization (AEO) is optimizing content to be selected as the direct answer by AI answer engines and assistants. It overlaps heavily with GEO; some vendors use AEO and GEO interchangeably.

AI Overviews

AI Overviews are Google's AI-generated answer summaries shown above traditional search results. They synthesize information from multiple web pages and cite sources, and can significantly reduce clicks to individual websites.

Answer engine

An answer engine is a system that returns a direct, synthesized answer to a query instead of a list of links. ChatGPT, Perplexity, Google AI Overviews and Copilot are answer engines.

Share of voice (in AI)

Share of voice in AI measures how often your brand is mentioned or cited in AI answers for a set of prompts, relative to competitors. GEO tools track it to show your visibility across engines over time.

Citation

A citation is a link or source reference an AI answer attributes information to. Being cited drives referral traffic and signals authority; earning citations is the core goal of GEO.

Brand mention

A brand mention is any reference to your brand inside an AI answer, whether or not it links to you. GEO tools track mention frequency, sentiment and context across AI engines.

LLM (Large Language Model)

A Large Language Model is an AI system trained on vast text data to generate human-like responses. LLMs such as GPT, Claude and Gemini power the answer engines that GEO aims to influence.

RAG (Retrieval-Augmented Generation)

Retrieval-Augmented Generation is when an AI model fetches live or indexed documents at query time and generates its answer from them. Engines using RAG can cite current web pages — which is why crawlable, well-structured content can be surfaced.

Hallucination

A hallucination is when an AI states something false or fabricated with confidence. In a brand context, an engine may misstate your pricing or features; some GEO tools flag hallucinations about your brand.

Answer block

An answer block is a short, self-contained 40–60 word passage that directly answers a question near the top of a page. Because it is easy to extract, answer blocks are frequently quoted verbatim by AI engines.

Structured data (Schema.org)

Structured data is machine-readable markup (using Schema.org vocabulary) that labels the meaning of page content — prices, FAQs, articles. It helps search and AI engines extract facts accurately and is a common GEO best practice.

AI crawler

An AI crawler is a bot that fetches web pages for an AI system, such as GPTBot, OAI-SearchBot, PerplexityBot, ClaudeBot and Google-Extended. Allowing these crawlers in robots.txt is a prerequisite for being cited.

Zero-click search

A zero-click search is a query answered directly on the results page — by an AI Overview or featured snippet — so the user never visits a website. AI answers have sharply increased zero-click behavior, raising the value of being the cited source.

New to this space? Start with How to get your brand cited in ChatGPT & Perplexity.