The operating system is the most important piece of software for a server or any computer. Often referred to as a platform in the web hosting environment, this software is responsible starting and shutting down the server, communicating with computer hardware and allowing the installation of various other software packages. If you are like most users, the operating system you are familiar with is Windows, the popular software developed and distributed by Microsoft. In the hosting arena however, several platforms exist, with Unix and the open-source Linux operating system being among the most widely used. Although the web server application is extremely important, the operating system is the heart of the server hardware. Because the platform acts as the core of the computer, it must be installed and configured before implementing any other applications.