Compare processes and threads in Linux and Python

Describe how a process and a thread differ on Linux. Next, explain how Python changes the picture (for example, the GIL), and when Python threads are preferable to Python multiprocessing for performance. Overview: This question tests knowledge of operating-system-level concurrency versus language-level concurrency, particularly the Linux process/thread distinction, Python's Global Interpreter Lock, and the performance trade-offs between Python threading and multiprocessing.