Wikipedia has a great article here, describing the several possibilities of IPC.
Mostly IPC is refered to as communication between processes on the same host.
Therefor you are referring to 'cross plattform' it is dependant if you mean only the .Net Framework or also communication between .Net Framework applications and applications written in other Languages. Additionally you are mentioning that you are 'new to windows'.
When you are talking about the .Net Framework Core which is available for Windows and Linux you could eg. use Protobuffers where you can find an article here. This way you can use normal Network / Named Pipe for communication.
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