Gosfather, you heard something but had no idea, let me tell you in simple how computers communicate.
You go to a web site www.google.com, actualy try nslookup www.google.com
Your going to some IP address (nslookup resolves a DNS name to an IP).
But then you know their address specific service from google.com…
For that you need to go for a specific room number, room 80 handles web trafic.
And not only room 80, often also room 8080, or some number choosen by the destination server.
So then you can brouwse to google
Its not that google can brouwse to you, first of all you dont have a room 80 at your apartment as you dont run a web server.
And also your firewall know that web trafic is to from your requests on the internal side only.
But then you want to send an Email, Email isnt handled by room 80, thats done by room 25 of mail.google.com
There you can sent your email to their mail server, but to retrieve Email from their server… well then you might need another room number
for example room 110, oh sure they have sky scrapers there.
So You use an application, that make use of an IP netwerk to find servers, where you use protocols who talk to a room number, acka socket.
A computer uses sockets depending on the software that is installed on it, and there are standard room numbers, and sometimes they change room numbers, here is list of such numebrs on wikipedia https://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers
And whats that UDP /TCP talk ?..
Well all applications use TCP or UDP or both as a way of talking.
For example an Email or a website uses TCP, so every email data is controled delivered with a recieve validation return.
But sometimes you dont care that every data is guaranteed delivered and resend if data was missing.
For example when you do video skype, your more concerned that your voice is clear, while the video stream might be blurry once in while. To make that possible they dont check if all data got recieved and they dont resend data, they just boradcast and you just recieve what you can, and if you miss a bit of data it wont be a problem, because you dont mind much about it, as delivery checking would only take more bandwidth from you video stream.