Programs that want to receive or send data across the network do so using a port. A firewall (in the sense of a firewall on your computer) is basically a program that sits between the rest of your programs and your network connection and determines what programs should be allowed out to the network and what incoming connections should be allowed to talk to your programs.
This is “increasing security” by making sure you don’t let incoming connections talk to whatever happens to be running on your computer that might be listening for network traffic.
I can provide a more ELI5 explanation if you would like it.
Programs that want to receive or send data across the network do so using a port. A firewall (in the sense of a firewall on your computer) is basically a program that sits between the rest of your programs and your network connection and determines what programs should be allowed out to the network and what incoming connections should be allowed to talk to your programs.
This is “increasing security” by making sure you don’t let incoming connections talk to whatever happens to be running on your computer that might be listening for network traffic.
I can provide a more ELI5 explanation if you would like it.