If you get a hosting server of your own, it will operate independently, so it will have its own Operating System and you can later install server side apps directly or script-driven sites through a hosting Cp. While keeping the Os updated isn't always considered fundamental, it can be a really important task for a number of reasons. A newer Operating system version might have better support for certain hardware, so you might get better performance for the websites and web applications that you install. Your server shall also be more safe because updates normally include security patches which deal with small problems which may allow 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 Os in order to work effectively and with their full capabilities.