The University of Chicago
If you are just starting with Unix, you should probably begin by reading the Unix: Getting Your Feet Wet document. If you're already using Unix, or know the information in the "Unix: Getting Your Feet Wet" document, this "Basic Unix" document includes a lot of further information.
So What is Unix, Exactly
Unix is a computer operating system first developed at Bell Labs (and, to get the legal language out of the way, a trademark of AT&T Bell Laboratories). An "operating system" is a master program which coordinates other programs' activities and manages files.
Unix is a computer operating system first developed at Bell Labs (and, to get the legal language out of the way, a trademark of AT&T Bell Laboratories). An "operating system" is a master program which coordinates other programs' activities and manages files.
One of the most popular and widespread operating systems in the world, Unix runs on more brands of computers than probably any other operating system in existence. This is partly because Unix is "portable": it is written in C, a high-level, machine-independent language. Programs written on one Unix machine can be easily adapted to other Unix machines (C is particularly well-integrated with the operating system itself).
In addition, Unix is based on a collection of small, easily understood utilities which allow you to connect them in many different ways (and in ways that the authors did not predict), building procedures and sophisticated tasks to suit your own needs. This "Unix philosophy" is often contrasted with monolithic programming environments (IBM mainframes or the Macintosh *** are sometimes mentioned) in which you can only perform tasks the system designers could predict; such systems, while becoming increasingly complex, often have bells and whistles you may not use, and lack those you want.