GEO Knowledge Base

Core Concepts

Generative Engine Optimization (GEO)

The practice of optimizing a brand's entities, content, and structured data so LLMs cite it when generating answers in ChatGPT, Gemini, Perplexity, and AI Overviews. Full guide →

Answer Engine Optimization (AEO)

Optimizing content to be chosen as the direct answer on answer-first surfaces — featured snippets, voice assistants, and AI chat interfaces.

Large Language Model (LLM)

A neural network trained on large text corpora that predicts and generates language — the reasoning engine behind ChatGPT, Claude, and Gemini.

Retrieval-Augmented Generation (RAG)

A technique where an LLM pulls live documents from an index at query time and uses them as context, grounding output in verifiable sources.

Zero-Click Search

A search session that ends without a click because the engine already displayed the answer inline — now the dominant behavior on AI surfaces. See the data →

Grounding

The process by which an AI system anchors generated text to retrieved source documents so output can be attributed rather than hallucinated.

Hallucination

An AI-generated statement that sounds authoritative but is factually wrong or fabricated, typically from weak grounding or missing source data.

Ranking & Trust Signals

AI Answer Share

The percentage of AI-generated answers for a query set that cite or recommend a specific brand — the GEO equivalent of share-of-voice. Methodology →

Citation Authority

How frequently and credibly a domain is cited by trusted third-party sources, used by AI systems to weight source trust.

Information Gain

A ranking concept measuring how much new, non-redundant information a page adds relative to what an AI already knows — favours original research.

Brand Confidence

The degree to which an AI is confident that a brand is real, reputable, and unambiguous — a composite of entity clarity, citations, and reviews.

E-E-A-T

Experience, Expertise, Authoritativeness, Trustworthiness — Google's quality framework, now extended as a trust signal across AI surfaces.

Entity Salience

How prominent and disambiguated a named entity is within content — a key factor in whether an LLM links that content to the right brand.

Structured Data & Technical

JSON-LD

JavaScript Object Notation for Linked Data — the recommended format for embedding Schema.org structured data inside HTML pages. Templates →

Schema Markup

Machine-readable metadata drawn from Schema.org that describes entities and relationships on a page so engines and LLMs parse them reliably. Templates →

Schema Graph

An interconnected set of Schema.org entities on a site linked via @id references, producing a miniature knowledge graph unique to the brand.

Knowledge Graph

A structured database of entities and their relationships — used by Google, LLMs, and AI assistants to reason about real-world concepts. Full playbook →

Entity

A uniquely identifiable thing — person, organization, place, product, or concept — that can be referenced across a knowledge graph.

@id Reference

A JSON-LD mechanism for referring to a previously declared entity by its canonical URL, avoiding duplication across schema graphs.

llms.txt

A proposed plain-text file at a site's root that gives LLM crawlers a curated map of the most important content — analogous to robots.txt.

Speakable Markup

Schema.org markup that tags sections of a page suitable for text-to-speech playback by Google Assistant, Siri, and Alexa.

AI Platforms & Surfaces

ChatGPT Search

OpenAI's in-product search surface inside ChatGPT that browses the live web and cites sources when answering queries.

Google AI Overviews

AI-generated summaries at the top of Google search results for eligible queries, citing a small set of source URLs.

Google AI Mode

A conversational, AI-first Google search experience that replaces ten-blue-links with a generative answer and supporting citations.

Perplexity

An AI answer engine combining web retrieval with LLM synthesis, known for prominent inline source citations.

Claude

Anthropic's family of conversational LLMs used in ChatGPT-style assistants, coding tools, and enterprise AI workflows.

Gemini

Google's multimodal LLM family powering AI Overviews, AI Mode, and the standalone Gemini assistant.

ChatGPT Atlas

OpenAI's agentic browser that lets ChatGPT navigate, read, and transact on websites — introducing new citation and visibility dynamics.

Perplexity Comet

Perplexity's agentic browser, performing research and multi-step tasks while exposing source citations throughout the session.

Local & Entity Signals

NAP

Name, Address, Phone — the core local-business identifiers that must stay consistent across a brand's website, directories, and structured data.

LocalBusiness Schema

The Schema.org type used to describe a physical business location — address, hours, services, and geographic coordinates.

AggregateRating

A Schema.org property for the aggregate score and review count of a business or product — used to render star ratings and trust signals.

Google Business Profile

Google's free local-business listing product (formerly Google My Business) feeding Maps, local pack results, and AI local recommendations.

Place Entity

A Schema.org entity for a physical location, used with LocalBusiness to carry geo, accessibility, and amenity data.

Local Citation

A mention of a business's NAP on a third-party directory or authoritative site, used as a corroborating signal for local and AI search trust.