If you get a server of your own, it will operate independently, so it'll have its own Os and you'll be able to later install server side applications directly or script-driven sites via a hosting Cp. Though keeping the Os updated is not always considered a necessity, it can be a very important task for a number of reasons. A newer Operating system version could have better support for certain hardware, so you might get better performance for the websites and web applications which you install. Your server will also be more secure because updates often include security patches which resolve small issues which may allow unauthorized individuals to access your content. Last, but not least, more modern script versions, which are also released for both increased security and for additional features, may require a later version of the Os in order to work correctly and with their full capabilities.