I'm aware that User Level threads are created on the User Mode( no privileges) and Kernel threads are created in the Kernel Mode( privileged). I am also aware that Processor threads are hardware threads that operate on Kernel Threads( I hope I am correct by putting it in this way)

Here is my confusion:-

1. User Level threads are not recognized by the OS as they are created, maintained and destroyed on the User Level. The OS doesn't see a multithreaded process from the User Mode as being multithreaded. It treats it as a single threaded process. Therefore, this program cannot take advantage of Multiprocessing, I guess it cannot take advantage of hyperthreading as well since it appears as single threaded in the OS. So what's the use of Multithreading in this case? I mean the computation time will still be the same