# Site search API

Sitefinity CMS Search uses the Publishing system in order to collect data that should be indexed. It registers the `SearchIndexOutboundPipe` that listens for changes in Sitefinity CMS and pushes them to the search index, using the active Search service.

The following diagram shows how a page content is pushed to the Search service index when the user publishes it. Other content in Sitefinity CMS is indexed in a similar manner. The difference between indexing different content types is that each of them comes from a different `InboundPipe`.

/documentation/sitefinity-cms/sf-images/default-source/developers-guide/search_pushdatatoindex_sequencediagram.png?sfvrsn=0[![Search_PushDataToIndex_SequenceDiagram](https://www.progress.com/documentation/sitefinity-cms/assets/d5930bab607b587aac8b62589ade967c/search_pushdatatoindex_sequencediagram.png "Search_PushDataToIndex_SequenceDiagram")](https://www.progress.com/documentation/sitefinity-cms/assets/d5930bab607b587aac8b62589ade967c/search_pushdatatoindex_sequencediagram.png)