What is RPC in cryptocurrencies and why are they needed?

RPC (Remote Procedure Call) is a method of remote interaction with other servers, providing the ability to run applications in a separate location. For Metamask users, RPC allows access to server nodes on a specific network. When creating an account, the user is automatically linked to the blockchain via RPC. By adding a custom RPC to Metamask, you can disconnect from overloaded nodes and connect to freer ones.