First, we will briefly explain the RPC protocol, why it emerged, and its utility. Then, we will see how gRPC works: the types of channels that can be created, the medium (Protocol Buffers) used to communicate between client and server, some features and utilities, and a small demo with JavaScript (client) and Python (server) code. Finally, we will look at the main differences between (g)RPC and other communication protocols/standards such as HTTP REST APIs or WebSockets.