If you get a server of your own, it will work independently, so it will have its own Os and you can later install server side applications directly or script-driven sites via a hosting Cp. Though keeping the Operating System updated is not always considered fundamental, it can be a very important task for a number of reasons. A more modern Operating system version may have better support for specific hardware, so you might get better performance for the websites and web apps that you install. Your server will also be more protected because updates normally include security patches which fix small problems which may permit unauthorized people to access your content. Last, but not least, more modern script versions, which are also released for both boosted security and for additional features, may require a later version of the Operating System in order to work properly and with their full capabilities.