In terms of features, Unix and Linux are quite similar. Linux is a variant of Unix, like SCO-Unix, HP-Unix and other Unix like operating systems. Most, if not all, programs available for any Unix-like operating system are also available for Linux. Actually Linux is an affordable alternative to the more expensive Unix operating system(commercial). It allows users to develop and test Unix software without having to spend too much money to buy the operating system. Linux is a product of the free software movement, giving it unique benefits. It saves you money, but also, because the source code is freely available, users aren't dependent on a vendor to release fixes and add new features. They can do it themselves, then recompile the kernel anjd it becomes more reliable, because more people examining the source code means fewer bugs.
The goal of Linux is to develop a free Unix system that could be run on both a personal level and on large network servers.
Although the source code for Unix and Linux is completely different, from the users end the main difference between Unix and Linux is that the former is costly, while Linux is free.
Other inexpensive versions of UNIX exist as well, like
FreeBSD, [url="http://www.openbsd.org"]OpenBSD,
NetBSD
To download linux, if you have a fast network connection, go to
http://sunsite.unc.edu/pub/Linux/ .
If you don't have a fast network connection or not
experienced in downloading large distributions, the
recommend you click on the RedHat 6.2 book on the
https://www.unix.com homepage and purchase book, CDROMs, etc
to install. The small price for the OS with documentation
and CDROM are well work the money.