What is GraphQL?

It is just a 'specification', developed and open sourced by facebook to optimise RESTful API calls.

• a library
• a framework
• a (programming) language
• GraphQL SDL is a query language for an API

Why do we need further optimisation over REST?

REST is good, but is really inefficient :

• Over-fetching - we fetch more than we need
• Under-fetching - we need to make multiple API calls to fetch complete data. i.e → a single API call isn't enough to get us the data in the format we desire (on the frontend)

As a RESTful application gets more complex, the communication between frontend and backend server becomes more and more complex, and developers need to tailor API endpoints specific to the frontend application. This causes the backend application to become intractable to the current state of frontend application, making it difficult for the developers to maintain and make future changes.

Let REST rest in peace.