multiples shells. / threads.

I understand that a new thread is created for each instance of an async shell and that a degree of parallelism can be achieve by running multiple shells.
I get the feeling however that multiple thread objects do not achieve this same degree of parallelism.
Is there any advantage to multiple threads in xojo?

The advantage of the thread class is to separate out a long process from the UI so it doesn’t block your app completely. Other than encapsulation and ease of programming, you don’t get a huge benefit from using more than one additional thread. Using a shell, you can take advantage of more than one cpu core and gain processing power.