It's the one thing when I'm configuring things that makes me wince because I know it will give me the business, and I know it shouldn't, but it does, every time. I have no real idea what I'm doing, what it is, how it works, so of course I'm blindly following instructions like a monkey at a typewriter.
Please guide me into enlightenment.
The top cat uses ports to sort messages based on application.
Think pigeon holes, applications usually use protocols which are assigned a number by convention. The application gets it's message out of it's assigned ports instead of having to sort through all the messages.