Remote Procedure Call (RPC) is a client-server mechanism for interprocess communication. Note that the RPC client and the RPC server communicate using TCP/IP, which means that they can exist in different machines.
In order to develop the implementation of an RPC client or RPC server, you will need to follow some steps and call some functions in a given way. Neither of the two implementations is difficult; you just have to follow certain steps.
Also, visit the documentation page of the net/rpc Go standard package that can be found at https://golang.org/pkg/net/rpc/.
Note that the presented RPC example will use TCP for client-server interaction. However, you can also use HTTP for client-server communication.