Front I/O ports on the front of a case

Question

I have seen so many cases with front usb ports etc, but obviously they couldn't fit every motherboard, so I was wondering how they connect, do they come with a plug that connects to a sata port or pci express or something, my question is just: how do those front i/o ports connect and interact with the computer

Answer 1

They are pretty much standardized and are just little pins that stick up in a certain configuration:

These pins look like this:

Answer 2

They're just electrical extensions of ports already found on the motherboard, just as an extension cord is an electrical extension of the wall socket.