There are three major kinds of Linux, commercial, non-commercial, portable (embedded). The commercial is made and aim toward use as servers with in a company or business. The non-commercial is made and aimed toward home use and is well rounded to where it can be easily used as ether a desktop, or as a home/personal server. The portable or embedded version is made for use in portable devices such as some cell phones which support an
OS, or some
PDA's which also support an
OS. There is also a price difference, while the non-commercial and the portable version of Linux may not cost you a thing, the commercial version can be very costly mostly because most distributors sell you a special made server that supports their distro instead of just sending you a disk with the
OS on it. Some also include tech support and system administration by professionals.