This is a link jack/parallel port.
As you probably haven't anymore a parallel port on your computer (or you have an adapter or a very old computer) I recommend to don't use this link.
This link often is an homemade link. It 's very to make it, I have done mine of course but I don't use anymore.
By the past, you were able to purchase one too. The parallel port is a 25-pin parallel port like old printers port