Why does my python script continue while if __name__==__main__ runs?

Below is a simplified version of a problem I'm facing. When I run my code, example below, why does the script run code below the if _name__==__main_ section while the function which sits underneath the if statement is still running? I thought the p_1.join() command should block the script from continuing until the separate process has finished. In the output below I'm expecting the word "Finished" to only be printed when all of the script has concluded - but instead it is being printed second and then last.

In the past I have used poolexecutor for similar problems; but in this project I need to start each process individually so that I can assigned separate independent functions to each process.

import time
from multiprocessing import Process, Queue

def a(x,q):
    time.sleep(3)
    q.put(x*x)

q=Queue()
def main():
    print("Main Function Starts")
    p_1 = Process(target=a, args=(5,q))
    p_1.start()
    p_1.join()
    b= q.get()
    print(b)
    print("Main Function Ends")

if __name__ == '__main__':        
       main()

print("Finished")

**Output:**
Main Function Starts
Finished
25
Main Function Ends
Finished