If you get a hosting server of your own, it will operate independently, so it'll have its own Operating System and you could later install server side applications directly or script-driven internet sites through a hosting Control Panel. Although keeping the Os updated is not always considered an absolute necessity, it can be a rather important task for a number of reasons. A newer Operating system version could have better support for specific hardware, so you could get better performance for the websites and web applications that you install. Your server shall also be more safe since updates normally include security patches that fix small problems which may enable unauthorized people to access your content. Last, but not least, more recent script versions, which are also released for both enhanced security and for additional features, may need a later version of the Operating System in order to work correctly and with their full capabilities.