An Operating System is the software that communicates with the hardware of a PC and serves as the intermediary between applications and the hardware, which includes peripheral devices such as a printer, a computer mouse or a keyboard. When you run software, it transmits requests to the OS through an API (Application Program Interface) and the interaction is done through a command line or a Graphical User Interface (GUI). Identical to a personal computer, web hosting servers also have an Operating System that serves as a host for any software installed on them, including script apps or server-side software such as a flash server, a VOIP server, and so on. A virtual machine can be generated on a physical one, so it is possible to install a guest OS on it and have a different system environment in contrast with the physical server host OS.
