API FOMO: REST, gRPC or GraphQL?

You want to create an API in .NET. So you use Web API right?

In fact, there are more choices which might be far more suitable for your situation.
Not only REST with Web API is possible but also gRPC and GraphQL. Come see this session to see how they work side by side. But, maybe more importantly I'll answer the question: When to use what and why?