The RESTful Web Services module provides display, row, and format plugins that allows you to export content entities to a serialized format. The REST Export display plugin allows you to specify a path to access the RESTful endpoint and properly assigns the Content-Type header for the requested format.

The Serializer style is provided as the only supported style plugin for the REST export display. This style plugin only supports row plugins that identify themselves as data display types. It expects data from the row plugin to be raw so that it can be passed to the appropriate serializer.

You then have the option of using the data entity or data field row plugins. Instead of returning a render array from their render method, they return raw data that will be serialized into the proper format.

With the row plugins returning raw format data and the data serialized by the style plugin, the display plugin will then return the response that is converted into the proper format via the Serialization module.