Every single notebook or desktop or web server is run by an Operating System - the low-level program that interacts with the computer hardware, including peripheral devices such as a mouse and a printer, as well as any applications that are currently installed on the 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 OS. On a web server, each and every application runs within the parameters established by the OS as well - priority, physical memory, processing time, etcetera. This is valid for both standard website scripts and server-side software like a media server. In case a virtual server is set up on a physical one, there can be two different Operating Systems, named guest OS and host OS, which means that you'll be able to set up a different software environment on the same machine.
Multiple OS in Dedicated Servers
If you decide to get one of our dedicated servers, you'll find three Operating Systems on the order page because we want to give you a broader choice with regard to the system environment on your server as different apps can have particular requirements. CentOS, Ubuntu and Debian feature different modules developed by their vast support communities, so you can select any of these OSs and take advantage of a stable and secure web hosting service. Depending on your choice, you will also have different Control Panels to choose from. Of course, we can always replace the Operating System if the one you have selected initially does not meet the requirements of the software which you want to run. We can also update the OS routinely to keep it as secure as possible with our Managed Services upgrade package.