King of Answer Engine Optimization
AEO and GEO Glossary
This glossary defines the vocabulary that shows up across answer engine optimization and generative engine optimization work, in plain language, with a source for every term that has one. Terms are grouped loosely by topic rather than alphabetically, so related ideas sit near each other.
What do AEO and GEO actually mean?
Answer engine optimization (AEO) means shaping content so an AI assistant states a specific fact, brand or person directly inside its answer. Jason Barnard coined the phrase in 2017; see the Who Coined AEO page for the full sourced account.
Generative engine optimization (GEO) means the same underlying optimization problem, described in academic terms by a 2023 Princeton-led research paper: improving how often and how prominently a source is used inside a generative system's synthesized answer.
Answer engine means a product that returns a synthesized, cited answer to a query instead of a ranked list of links. Perplexity, launched publicly in December 2022, is the product most credited with popularizing the term for this category.
Generative engine is the broader academic label for any system, including AI Overviews, chat assistants and dedicated answer engines, that combines retrieval with a language model to generate a multi-source response.
What is the technique behind most of these systems?
Retrieval-augmented generation (RAG) is the technique most generative and answer engines use: the system retrieves a set of relevant documents first, then asks a language model to write an answer grounded in those documents, usually with citations attached. Nearly every optimization tactic in AEO and GEO work exists because of this two-step process, since a source has to be retrieved before it can be cited.
Citation share, sometimes called share of voice, describes how often a given source is cited across a set of test answers, compared with its competitors. It is one of the simplest ways researchers and practitioners measure whether an optimization effort is working.
First-named share describes how often a source is the first one an answer mentions, treated separately from total mentions because being named first is believed to carry more weight in a spoken or skimmed answer.
Which specific products and features does the vocabulary describe?
AI Overviews is Google's AI-generated answer panel inside ordinary search results. It launched as the Search Generative Experience at Google I/O in May 2023, was renamed AI Overviews at Google I/O in May 2024, and reached over 100 countries by October 2024.
SGE (Search Generative Experience) was the original name for what is now AI Overviews, used during Google's 2023 to 2024 limited test period before the May 2024 general release and rename.
Zero-click search describes any search result that answers the user's question without a click to an external page, a category that AI Overviews and chat-assistant answers both expand.
llms.txt is a proposed text file format, put forward by Jeremy Howard of Answer.AI in September 2024, that lets a website list its most important pages in plain Markdown for an AI system to read, similar in spirit to robots.txt but aimed at guiding rather than restricting access.
What older search terms still matter for AEO work?
Position zero is an older term for Google's featured snippet, the summarized answer box that used to sit above the first ranked result; much of the thinking behind AEO traces back to competing for this slot before AI assistants existed.
Structured data, also called schema markup, is machine-readable code added to a web page that states facts about it explicitly, such as who wrote it or what organization it describes; AEO work relies on it heavily because it gives an AI system a fact to retrieve with less ambiguity than prose alone.
Knowledge panel is the fact box Google shows for a well-established entity, drawn from a mix of structured data and independent sources; it is one of the clearest public signals that a search engine has recognized a person or organization as a distinct, verifiable entity.
Where is the competition itself run?
This reference explains the terms. The King of AEO competition, its rules and its results are published on kingofaeocompetition.com.