What about GraphQL as an API choice?

The course is really high level at the moment. I am in the Web Application & Software Architecture course referring to the What is REST API lesson (Module 1). I would like to understand how GraphQL could be a valid API choice rather than REST or would modern mobile and web apps leverage both GraphQL and REST APIs together in some form? If yes, how would that look?

@Zaki Lesson regarding GraphQL will be added soon.