REST vs. gRPC vs. GraphQL

1. Three Tools, Three Different Jobs

"REST or gRPC?" sounds like a versus question. The strongest answers do not accept that framing.

Mature systems typically use more than one of these, in different places. That is because they optimize for different things. Your job is to know what each one is for, then assign each edge of your design the right one.

REST is the convention of using plain HTTP with JSON. Resources are URLs. Actions are HTTP methods like GET and POST. Responses are JSON, which is text a person can read.