There are of course quite a few operating systems around these days such as windows, linux, unix and others. Since Unix and Linux sound sort of similar you may be wondering if they are in fact more or less the same and the answer is yes and no. That may not seem too helpful, however unix administration is not so alien to anyone who is familiar with linux and the differences can soon be picked up for the most part. If you have a beard, chances are Unix is coded into your DNA anyway.
Linux actually started life as a clone of unix so as you’d imagine they share similarities at many levels. Over the years many applications on one OS have been ported to the other so even when dropped in at the deep end you will not be totally lost. The filesystem may be organized a little differently but a short time spent exploring will soon reveal its secrets.
Since the early days, Unix has come a long way and modern versions of the likes of Solaris are quite polished and relatively user friendly. If you find yourself tasked with unix administration at work and need to get up to speed quickly you should find a good book which will guide you in the right direction and in fact I highly recommend the rather massive UNIX and Linux System Administration Handbook which has truck loads of info and actually shows you how to perform the same tasks in several versions of Unix and Linux so it is ideal for the linux syadmin who needs to take on unix administration or the unix admin who has to tackle some linux boxes.
I actually own that very same book and it has proved itself invaluable over the last couple of years, although it weights about 20 kg (only a slight exaggeration!) so you may want to get it for Kindle instead which I unfortunately did not do! Live and learn..