unix or linux... isnt that like asking car or 4 wheeled passenger vehicle?
Essentially you learn unix systems of which linux is a part of. Im sure I will get heat from the linux purists who say "linux is not unix". When you boil it down to the basics, you have mostly the same commands, a few might be vendor specific, but there is no apples to oranges comparison in my book. Once you learn unix, you can pretty much hop around to whatever flavor you like, bsd, linux, solaris. Its a bit of a stretch to get into the more obscure vendor flavors HPUX, AIX but you can still manage. Linux is a very user friendly platform to learn on, but if you can bear it, learn the command line interface (CLI), it gets you in "the club" for unix street cred.
Essentially you learn unix systems of which linux is a part of. Im sure I will get heat from the linux purists who say "linux is not unix". When you boil it down to the basics, you have mostly the same commands, a few might be vendor specific, but there is no apples to oranges comparison in my book. Once you learn unix, you can pretty much hop around to whatever flavor you like, bsd, linux, solaris. Its a bit of a stretch to get into the more obscure vendor flavors HPUX, AIX but you can still manage. Linux is a very user friendly platform to learn on, but if you can bear it, learn the command line interface (CLI), it gets you in "the club" for unix street cred.