Every desktop or notebook or server is run by an Operating System - the low-level program which interacts with the computer hardware, including peripheral devices such as a mouse or a printer, as well as any applications that are currently installed on your system. Any program input through a command line or a Graphical User Interface (GUI) is processed by sending an Application Program Interface (API) request to the Operating System. On a web server, each and every app runs within the parameters specified by the OS as well - priority, physical memory, processing time, and so on. This is valid for both standard site scripts and server-side software such as a media server. If a virtual server is created on a physical one, there can be two separate Operating Systems, referred to as guest OS and host OS, so you'll be able to set up a different software environment on the very same machine.
Multiple OS in Dedicated Servers
If you decide to purchase one of our dedicated servers, you shall find three Operating Systems on the order page as we want to give you a wider choice with regard to the system environment on your machine as different applications could have certain requirements. CentOS, Ubuntu and Debian include different modules developed by their large support communities, so you can select each of these OSs and enjoy a stable and risk-free hosting service. Depending on your selection, you'll also have different Control Panels to choose from. Of course, we can always change the Operating System in case the one you have selected at first doesn't meet the requirements of the software which you'd like to run. We can also update the OS routinely to keep it as secure as possible through our Managed Services upgrade package.