Each notebook or desktop or web server is run by an Operating System - the low-level program which communicates with the computer hardware, including peripheral devices such as a mouse or a printer, as well as any applications that are currently installed on the system. Any program input using a command line or a Graphical User Interface (GUI) is processed by sending an Application Program Interface (API) request to the OS. On a web server, every single app runs within the parameters specified by the OS as well - priority, physical memory, processing time, and so on. This goes for both standard site scripts and server-side software like a media server. If a virtual server is created on a physical one, there can be two independent Operating Systems, called guest OS and host OS, so that you'll be able to set up a different software environment on the very same machine.
Multiple OS in Dedicated Servers
In case you decide to acquire one of our dedicated servers, you shall find three Operating Systems on the registration page because we want to give you a broader choice for the system environment on the server as different apps can have certain requirements. CentOS, Ubuntu and Debian include different modules developed by their huge support communities, so you can select any of these OSs and benefit from a stable and safe web hosting service. Depending on your decision, you'll also have different Control Panels to choose from. Needless to say, we can always change the Operating System if the one you've selected initially doesn't meet the requirements of the software which you intend to run. We can also upgrade your OS regularly to keep it as secure as possible using our Managed Services upgrade package.