Starting in 2004, a new way of connecting hard drives to computer motherboards started to emerge. A SATA cable has a rubber exterior and is about the thickness of a pencil, as opposed to the broad, flat ribbon cable associated with the old PATA cables. SATA drives are faster, and are easier to connect; but your old hard drive will almost certainly be the old PATA ribbon cable.
However, new computers will almost certainly use a Serial ATA hard drive. Fortunately, most optical drives, such as DVD burners and CD readers, still use the old PATA specification.