# Sunucu
from socket import *
import sys

serverSocket = socket(AF_INET, SOCK_STREAM) 
serverPort = 100 
serverSocket.bind(('',serverPort))  belirtmektedir.

serverSocket.listen(1)

while True:

    connectionSocket,addr = serverSocket.accept() 
    try:
        message = connectionSocket.recv(4096).decode()
        
        filename = message.split()[1][1:]
        with open(filename,"rb") as f:
            output = f.read()

        connectionSocket.sendall(output)
        connectionSocket.close()

    except IOError:
        response = b"HTTP/1.1 404 Not Found rnrn"  
        connectionSocket.send(response)
        connectionSocket.close()

When we only give the value 80 to the serverPort variable, the web server is running and can be accessed. However, when I give port 100, which I have checked is not used, as in the example, it does not work and cannot be accessed. What is the reason of this?