Remote Procedure Call (RPC) is a protocol that allows a program to request a service or function execution from a different program or system, even if it's located on a separate network. RPC abstracts the communication process, making remote calls appear like local function calls, simplifying the coding process.

RPC works by sending a request to a remote server, executing the requested function or procedure on that server, and returning the result to the caller. Popular implementations include gRPC, Apache Thrift, and XML-RPC, all of which help in building distributed systems by allowing different components to communicate efficiently.

RPCs are used in microservices architectures, client-server applications, and large distributed systems where components may be scattered across different servers but need to interact seamlessly. They offer an effective way to scale services while keeping the communication layer simple and efficient.