# Index Service The index service knows which document contains which keywords. ## Central Classes * [IndexService](src/main/java/nu/marginalia/index/IndexService.java) is the REST entry point that the internal API talks to. * [IndexQueryService](src/main/java/nu/marginalia/index/svc/IndexQueryService.java) executes queries. * [SearchIndex](src/main/java/nu/marginalia/index/index/SearchIndex.java) owns the state of the index and helps with building a query strategy from parameters. * [IndexResultValuator](src/main/java/nu/marginalia/index/results/IndexResultValuator.java) determines the best results.