[Wrexial33]

Think of your computer as having a big train station in it,  all these trains (network/Internet responses) are moving in and out, the incoming trains have to be directed to their specific part of the train yard to be processed, for instance you wouldn't want a coal car (maybe bit torrenting or something) to show up at the passenger loading bay (your outlook inbox). As such, each train is directed using different sets of signals like red blue red or something being used for coal and green blue green being used for passengers, these signals that tell a train where to go represent the port number, directing different network traffic to specific programs, making sure you get your email in you inbox and you torrents in your torrent client. When you setup a personal minecraft server on your pc or a server with other things going on, you need a port number to get to the minecraft server you want and not get directed to an inbox or some porn torrent server or something. For most larger minecraft servers however an ip address is used for a similar purpose, directing your minecraft connection to the proper location.