Glossary · 13 terms

GEO terms, defined plainly.

GEO introduces terminology that overlaps with but is distinct from traditional SEO. These 13 core concepts appear throughout the playbook — from readiness levels to the technical protocols underpinning Phase 4.

TL;DR

GEO introduces a set of terms that overlap with but are distinct from traditional SEO. This glossary defines the 13 core concepts used throughout the playbook — from the readiness ladder levels to the technical protocols (WebMCP, llms.txt) that underpin Phase 4. New to GEO? Start here before reading the phases.

Why this matters: GEO terminology is evolving fast and often misused. Precise definitions matter when briefing developers, writing content briefs, or evaluating vendor claims.

GEO (Generative Engine Optimisation)
The practice of making a website discoverable, citable, and transactable by AI-powered search and recommendation systems — the counterpart to traditional SEO for the LLM era.
AEO (Answer Engine Optimisation)
A subset of GEO focused specifically on getting your content quoted as a direct answer by AI systems like ChatGPT, Perplexity, or Google AI Overviews.
LLM / AI crawler
An automated bot operated by an AI company (e.g. GPTBot, ClaudeBot, PerplexityBot) that fetches and indexes web content to train or augment large language models.
llms.txt
An emerging open standard (similar to robots.txt) that lets site owners declare AI-specific access rules and link to key content for LLM consumption, placed at the root of a domain.
robots.txt
A plain-text file at the root of a domain that instructs crawlers which pages they may or may not access; AI crawlers respect it just like traditional search bots.
Schema.org / structured data
A shared vocabulary of JSON-LD markup embedded in HTML that tells search engines and AI systems what a page is about — product, FAQ, organisation, article — in a machine-readable format.
RAG (Retrieval-Augmented Generation)
An AI architecture where a model fetches live documents at query time to ground its answer in current facts, rather than relying solely on training-time knowledge.
Citation
When an AI system names or quotes your brand, product, or content in a generated answer — the primary success metric of GEO, equivalent to a top-ranking organic result in traditional SEO.
Readiness ladder
Hidden Layer's five-level framework (L0 Invisible → L4 Transactable) describing the sequential stages of AI readiness, where each level depends on the one below it.
Render gap
The discrepancy between what a browser displays (after executing JavaScript) and what an AI crawler actually sees (server-rendered HTML only), often causing LLMs to miss core page content.
Entity
A uniquely identified real-world concept — a brand, product, or person — that AI systems track across sources using @id anchors and sameAs links to resolve facts about it.
WebMCP
An open protocol that lets browser-based AI agents discover and invoke HTML forms as tools via data-toolname / data-tooldescription attributes and a /.well-known/webmcp manifest.
Cold recall
The ability of an LLM to accurately describe your brand from training data alone, without any retrieval or search — measured by Hidden Layer's geo_cold_recall score and the primary signal of long-term GEO progress.