What does a parallel cable look like?

There are two types, a 25 pin male to 25 pin female, and the most common, 25 pin male to a Centronix, which is what printers use.

There are 25 pin cables that is not are not printer cables, but they are very uncommon. Almost all the time when someone refers to a parallel cable they are referring to a printer cable, which is a 25-pin to Centronix cable.