# Lexical search

Concept · [Technical basics](https://ecosystem.samcarlton.com/technical)

Also called: keyword search, lexical, full-text search, exact match search, BM25

Search that matches the exact words in a query. It is fast and predictable but misses results that use different words for the same idea. [Similarity search](https://ecosystem.samcarlton.com/similarity-search) fills that gap.

**For example:** A lexical search for 'refund' misses an article titled 'Getting your money back'.

## Connects to (4)

- [Similarity search](https://ecosystem.samcarlton.com/similarity-search): Finding the stored items whose vectors are closest to a query's vector, so results match by meaning rather than exact words.
- [Hybrid search](https://ecosystem.samcarlton.com/hybrid-search): Combining keyword search and similarity search, so results match both exact terms, such as product codes, and overall meaning.
- [Vector database](https://ecosystem.samcarlton.com/vector-database): A database built to store embeddings and quickly find the items closest in meaning to a question, not just the ones that share its exact…
- [RAG](https://ecosystem.samcarlton.com/rag): Retrieval-augmented generation.

Map view: https://ecosystem.samcarlton.com/lexical-search