gRPC: what is it? An introduction...

The first time I heard about RPC, I was in a distributed systems class while completing my bachelor’s in computer science. I like it but didn’t fully understand why I should use it instead of REST. Time passed, and I started working at a company where the legacy services use SOAP. I remember thinking: “hm, that’s cool! It is like RPC but using XML instead! Years later, I heard for the first time about gRPC, but I’ve never fully understood it until now!