First, everyone should have a back up drive which is used to completely back up the hard disk's data. Any good, functioning drive should do. Thunderbolt drives are faster than other drives and also are more expensive to purchase. I would assume that the drive came with its own Thunderbolt cable. That should be plugged into the Thunderbolt port on your Mac. If you do not have a cable, then you can get one on (for example) Apple's web site which has good illustrations of the cable connecters. Get one that has the appropriate connecters on each end to match the ports that it will be plugged into. You may have to format the drive to work with whatever operating system you have installed. As to your question about whether the drive still works, only you can answer that. Plug it in and see if it works. If not, there are plenty of reasonably priced non-Thunderbird drives available which will serve you just fine. Most of them are compact, come with vendor provided USB cables and do not require external power.