The App Builder Data features let you add, edit, and use external data sources in the application you are developing. By default, App Builder for React comes with a mock Northwind data source which users can use for reference.
You can set up REST API data sources using OpenAPI (Swagger) file definitions by providing a direct REST API URL to the definitions file or by importing a Swagger file (JSON/YAML). Once connected, map the API data to your app’s components and customize how and when API calls are made.
In addition to this, App Builder also provides a UI for performing CRUD operations from within the grid. This is quite easy as the Grid provides Cell Editing, Row Editing, Row Adding, and Row Deleting UI out of the box.