If you get a server of your own, it will work independently, so it'll have its own Operating System and you can later install server side apps directly or script-driven sites through a hosting Cp. Although keeping the Os updated is not always considered fundamental, it can be a quite important task for several reasons. A more modern OS version could have better support for certain hardware, so you might get better performance for the internet sites and web applications you install. Your server shall also be more safe because updates usually include security patches which fix small issues which may permit unauthorized individuals to access your content. Last, but not least, newer script versions, which are also released for both increased security and for additional features, may need a later version of the Operating System in order to work correctly and with their 100 % capabilities.