If you get a server of your own, it will run independently, so it will have its own Operating System and you could later install server side apps directly or script-driven websites via a hosting Control Panel. Although keeping the Operating System updated is not always considered an absolute necessity, it can be a rather important task for a number of reasons. A newer OS version may have better support for specific hardware, so you might get better performance for the internet sites and web applications which you install. Your server will also be more protected because updates normally include security patches which deal with small issues that may enable unauthorized people to access your content. Last, but not least, newer script versions, which are also released for both improved security and for additional features, may require a later version of the Os in order to work properly and with their full capabilities.