REST is using HTTP protocol, and request-response

structured JSON objects.

▪ API interfaces design based on HTTP verbs like GET-PUTPOST and DELETE.

▪ gRPC is basically Remote Procedure Call, that basically

invoke external system method over the binary network

protocols.

▪ Payloads are not readable but its faster that REST APIs.

▪ 2 Main Approaches for Public and Backend APIs:

▪ RESTful API Design over HTTP using JSON

▪ gRPC binary protocol API Design

https://www.baeldung.com/rest-vs-grpc