What exactly is Python multiprocessing Module's .join() Method Doing?

Question

Learning about Python Multiprocessing (from a PMOTW article) and would love some clarification on what exactly the join() method is doing.

In an old tut

Answer 1

To wait until a process has completed its work and exited, use the join() method.

and

Note It is important to join() the process after terminating it in order to give the background machinery time to update the status of the object to reflect the termination.

This is a good example helped me understand it: here

One thing I noticed personally was my main process paused until the child had finished its process using the join() method which defeated the point of me using multiprocessing.Process() in the first place.