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