Semantic and Hybrid Search — Matching by Meaning
Keyword search has one incurable weakness: it matches words, not meaning, so it misses relevant results that use different vocabulary than the query. Semantic search fixes this by representing queries and documents as vectors of meaning and matching by proximity in that space — the technology behind modern RAG. But the surprising lesson of production search is that semantic didn't replace keyword; the best systems combine them. This post explains vector search and why hybrid retrieval wins.
Keyword search matches words, not meaning. Semantic search embeds queries and documents into a vector space and matches by proximity — the engine of RAG — but it's weak at exact matches. Why keyword and semantic have opposite strengths, and why hybrid retrieval (not replacement) is the modern default.