AI Search Glossary

AI Search Glossary: GEO, AEO, LLMO, AI Visibility, and Core Terms

ForecastsGPT Research Team 3 min readLast updated June 10, 2026

AI search introduces a new vocabulary. This glossary gives short, plain-language definitions of the terms that come up most often when measuring and improving brand visibility across AI answer platforms. Where useful, definitions link to the relevant ForecastsGPT service so you can see how each concept applies in practice.

Core concepts

Generative Engine Optimization (GEO)
The practice of measuring and improving how generative AI systems represent a brand inside their answers. Learn more in what is generative engine optimization.
Answer Engine Optimization (AEO)
Optimizing content to be used in direct answers from answer engines and assistants, with an emphasis on clear, answer-first information.
LLM Optimization (LLMO)
Work aimed at making content and brand information more legible and usable to large language models, so they describe a brand accurately.
AI Visibility
How present and accurately represented a brand is across AI answer platforms. Measured and improved through services like the AI Visibility Audit.

Measurement terms

AI Visibility Audit
A point-in-time benchmark of how AI platforms represent a brand, including competitor context and gaps. See the AI Visibility Audit service.
GPT Ranking Tracker
Recurring measurement of how a brand appears in AI answers over time across a fixed prompt set. See the GPT Ranking Tracker service.
Share of Answer
The proportion of relevant AI answers in which a brand appears, across a defined prompt set. Explained in share of answer.
Prompt Coverage
The breadth of buyer questions where a brand appears in AI answers. Broad coverage means visibility across many questions, not just a few.
Answer Sentiment
Whether a brand is described positively, neutrally, or with caveats within an AI answer.

Citation and mention terms

AI Citation
When an AI system references or visibly draws on a source while answering. See how to get cited in LLMs.
Brand Mention
Any time a brand is named within an AI-generated answer, whether or not a source is cited.
Owned Citation
A citation that references a source the brand controls, such as its own website or documentation.
Third-Party Citation
A citation that references an external source, such as a review site, publication, or comparison page.

Technical terms

Retrieval-Augmented Generation (RAG)
A method where a model retrieves relevant external information at answer time and uses it to generate a response, rather than relying only on training data.
Entity Optimization
Making information about who a brand is and what it does clear and consistent, so AI systems can identify and describe it confidently.
Query Fan-Out
When a system expands a single question into several related sub-queries to gather information before composing an answer.
Prompt Set
A defined, consistent list of buyer questions used to measure AI visibility comparably over time.
AI Referral Traffic
Visits that arrive from links shown within AI answers or assistant interfaces.

Platforms and surfaces

AI Overview
An AI-generated summary shown directly within Google search results.
Google AI Mode
A conversational AI experience within Google that answers questions in a chat-style format.
Perplexity
An answer engine that responds to questions with synthesized answers and frequently surfaces sources.
ChatGPT Search
Search and answer capabilities within ChatGPT that respond to questions, sometimes referencing sources.
Copilot
Microsoft's AI assistant, embedded across its products and search experiences.
Gemini
Google's AI assistant, integrated across its ecosystem and used for answering questions.

Putting the terms to work

These concepts come together in a measured GEO program. To see how they apply to your brand, start with an AI Visibility Audit or explore all services and pricing.

Written by

ForecastsGPT Research Team

ForecastsGPT Research Team

The ForecastsGPT Research Team publishes practical explainers, glossary entries, and technical guides on AI visibility, generative engine optimization, AI search measurement, and content readiness for AI answer platforms.

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