Compare remoting with remote connectivity
Remoting is the name of a specific Windows PowerShell feature, not to be confused with the more generic concept of remote connectivity. Remoting is a generalized way to transmit any command to a remote computer so it runs locally on that computer. The command that you run doesn't have to be available on the computer that initiates the connection. Only the remote computers must be able to run it.
The purpose of remoting is to reduce or eliminate the need for individual command authors to code their own communications protocols. Many command authors are already required to do this to ship their products. This is why many different protocols and technologies are currently in use.
Many commands implement their own communications protocols, although in the future many of them might instead be changed to use remoting. For example, Get-WmiObject uses RPCs, whereas Get-Process communicates with the computer’s Remote Registry service. Microsoft Exchange Server commands have their own communications channels, and Active Directory commands communicate with a specific web service gateway by using their own protocol. All these other forms of communication might have unique firewall requirements and might require specific configurations to be in place to operate.