VUser as Process Vs. VUser as Thread

I read the following somewhere:

"While running scripts using WinInet replay engine, we have to run VUser as a process instead of thread hence it requires more resources and load generators."

Is it compulsory to run VUser as a process, while running scripts using WinInet level data?

Is it compulsory to run VUser as a thread, while running scripts using Socket level data?

Can these be used interchangeably, like WinInet level data-VUser as thread and Socket level data-VUser as a process?

Regards,

Sachin