The terms UNIX hosting and Windows hosting refer to the operating system (OS) that is running on the server. The operating system, of course, is the software that allows the computer to function and manage all of the other hardware and software that is installed on it. Chances are good that you are reading this on a computer running a version of the Windows operating system, the most popular operating system in the world for personal and business computers. Other operating systems that are growing in popularity are Macintosh and various versions of Linux. However, the operating system you use on your computer is irrelevant to which type of hosting you choose. Here are some of the main features of UNIX and Windows: