Every single personal computer or server is run by an Operating System - the low-level program that interacts with the hardware equipment, including peripherals such as a mouse or a printer, and any apps that are 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 server, each app runs within the parameters established by the OS as well - priority, physical memory, processing time, etc. This is valid for both standard site scripts and server-side software such as a media server. In case a virtual server is created on a physical one, there can be two separate Operating Systems, called guest OS and host OS, which means that you'll be able to set up a different software environment on a single machine.
Multiple OS in Dedicated Servers Hosting
If you decide to acquire one of our dedicated servers, you will find three Operating Systems on the registration page because we want to give you a wider choice for the system environment on your machine as different apps could have certain requirements. CentOS, Ubuntu and Debian come with different modules developed by their large support communities, so you can select each of these OSs and benefit from a reliable and safe web hosting service. Based on your selection, you will 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 does not meet the requirements of the software that you would like to run. We can also upgrade your OS on a regular basis in order to keep it as secure as possible through our Managed Services upgrade package.