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:

• [Range](🔗)

• [Geographical distance](🔗)

• [Filter](🔗)

• [Terms](🔗)

• [Histogram](🔗)

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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.