Typical usages are _tag clouds_ and _faceted navigation_, which let site visitors restrict search results to selected categories, such as product types, price ranges, or author names.
Facets provide aggregated data based on a search query, and are requested and retrieved along with regular search requests. Note that they are scoped for the search query by default.
[Elasticsearch](🔗), upon which Optimizely Search & Navigation is built, features several facets ranging from simple to advanced.
The .NET client API in Optimizely Search & Navigation supports facets based on:
Facets and filters
Normally, facets are affected by filters, just like search results. However, via the [FilterHits method](🔗), you can retrieve facets without applying the filters applied to search results . Therefore, it is good to read up on the `
Filter` and `
FilterHits` methods, because there are significant differences between them when working with facets.