Query profiles let you consistently point your search application at a static endpoint, but give you the flexibility to change the actual query pipeline being used (and optionally, the collection and/or configuration parameters for the query pipeline).
For example, an e-commerce site might want to create a query pipeline to support a month-long promotion. After the query pipeline is configured, it can be easily enabled by changing the query profile in use by the front-end application to use the new pipeline.
To run a query through a query profile, use the REST API as described below. For CRUD operations, you can use either the REST API or the Fusion UI.
Query profiles in the REST API
Query profiles in the UI
Query profiles are configured at Querying > Query Profiles.