This is a doubt from my side from a very long time, So please explain this if possible.

An Example is take the new version of AMD's ryzen 5 4600H that has 6 cores and 12 threads. Assuming that In a normal Operating System, there're at least 20 different processes (For windows, we can see them in task manager) running simultaneously. How're these different from the 12 threads ? And how does these threads take care of these processes ?

I do know that these processes are indirectly threads, but how do these switch between processes ?

Also, is there'ny resource (book/something) that will explain the concepts of OS clearly using these analogies in the real world (like processors, thread info and OS level processes) ?