Python Web Scraping - Second Edition

How threads and processes work

Here is a diagram of a process containing multiple threads of execution:

When a Python script or any other computer program is run, a process is created, containing the code and state, as well as the stack. These processes are executed by the CPU cores of a computer. However, each core can only execute a single thread at a time and will quickly switch between them to give the impression that multiple programs are running simultaneously. Similarly, within a process, the program execution can switch between multiple threads, with each thread executing different parts of the program.

This means that when one thread ...