Protocols
gRPC
gRPC is a typed remote procedure call system commonly carried over HTTP/2.
How it works
A schema defines services and messages, then tooling generates clients and servers. Streaming and compact binary serialization suit service-to-service communication.
A concrete example
Illustrative: StreamTokens returns 50 protobuf messages over one server-streaming call.
Do not confuse it with REST
gRPC exposes typed procedures; REST usually exposes resource-oriented HTTP operations.