Aggregate Database data with Rest service results and expose single endpoint

In enterprise implementations, we need to deal with multiple data sources. it can be multiple databases as well as databases mixed with rest endpoints. this video explains how graphQL and aggregate all endpoints and release one endpoint to consumers.

A RESTDataSource is responsible for fetching data from a given REST API. Data sources are classes that encapsulate fetching data from a particular service, with built-in support for caching, deduplication, and error handling. You write the code that is specific to interacting with your backend, and Apollo Server takes care of the rest.