Glossary
The vocabulary, defined honestly
Ten terms you will meet in any conversation about AI and websites. Where we have measured the thing behind a term, the entry says what we measured and cites the note. Where the term is mostly marketing, the entry says that too.
| Term | In one sentence |
|---|---|
| AEO | AEO is the practice of getting a business’s facts into the answer a machine gives, rather than into a list of links a person clicks. |
| GEO | GEO is the same discipline as AEO, named for the generative side of the machine rather than the answering side. |
| AIO | AIO is the loosest of the three acronyms: a catch-all for making a website work for AI systems, used differently by different vendors. |
| llms.txt | llms.txt is a proposed convention: a Markdown file at /llms.txt that gives a machine a curated summary of a site and where to go on it. |
| Agent card | An agent card is a JSON file, conventionally at /.well-known/agent-card.json, that states who a site belongs to, what it offers, and where the machine-readable surfaces are. |
| WebMCP | WebMCP is an emerging browser-side standard for a website to publish callable tools — get a quote, look up an order — that an agent can invoke instead of filling in a form. |
| AI crawler | An AI crawler is a robot that requests pages on behalf of an AI operator — for training, for a search index, or on behalf of a person who just asked a question. |
| Answer engine | An answer engine takes a question and returns an answer, with citations if you are lucky, rather than a page of results to choose from. |
| Fact block | A fact block is a plain-text panel of buyer-question answers placed in the homepage itself, so an agent that fetches one page gets the facts on that fetch. |
| Entity stamp | An entity stamp is a hash of a signed-off fact profile, published with every superseded version, giving a tamper-evident history of what a business published and when — and, once that hash is anchored in a public ledger, a notarized and timestamped one. |
why a glossary
Three of these are the same thing wearing different hats
AEO, GEO and AIO get sold as three disciplines. They point at one mechanism: what a machine can recover from the page it actually fetched. Everything else on this list is either a file that helps it do that, a robot that does the fetching, or a record of what you published.
The distinction worth keeping is between the surfaces we have measured and the ones we have not. The fact block is measured: 78% of fact checks recovered against 30% in the control, agents stopping after 1.1 pages on average (Note 41). The fact file passes an audit and is close to useless as a discovery mechanism on its own — unpointed agents opened it 0 times in 18 visits (Note 15). Both statements are in the glossary because both are true.
Sources: MARKETING_NOTES_AGENT_VISIBILITY.md, Notes 15, 41.
free audit
See what AI sees on your site
Definitions are free. Finding out which of them is costing you enquiries takes a measurement.
One model fetches your homepage and answers buyer questions from it. You get the recovery score and the specific answers it could not find. That is the whole free tier: it shows you the problem, and the fix package is not included.