Lightweight-Heavyweight Process:

Lightweight Process: A thread is similar to a separate process, in that it can run independently of other threads. But it is lightweight, since the operating system doesn't have to give it its own memory space, and it shares memory with the other threads in the process. It runs within the context of a program because threads or sub-programs of a main application program.

Heavyweight Process: In heavyweight processes in between threads that belong to different programs. They demand separate memory