Semantic search — matching on meaning rather than on the exact words typed.
Why “we rank for the keyword” stopped being the whole answer
Text is converted into vectors — long lists of numbers positioned so that passages meaning similar things sit near each other. A search then becomes a question about nearness in that space rather than about which words matched.
The practical consequence: a page can be retrieved for a phrasing that appears nowhere on it, and a page stuffed with the exact phrase can be passed over for one that answers the question better. Exact-match repetition stopped being the mechanism some time ago; it just took the industry a while to stop selling it.
What to do instead
Cover the concept from the angles a buyer would actually take, in the words they would actually use, and answer the question rather than circling it. That is not a stylistic preference. It is what makes a passage land near the question in vector space.
Related: query fan-out, retrieval-augmented generation, generative engine optimization.