If you get a server of your own, it will operate independently, so it'll have its own Operating System and you could later install server side apps directly or script-driven internet sites via a hosting Control Panel. While keeping the Os updated isn't always considered an absolute necessity, it can be a really important task for a variety of reasons. A newer Operating system version might have better support for specific hardware, so you could get better performance for the internet sites and web applications which you install. Your server will also be more secure because updates normally include security patches that deal with small issues that may enable unauthorized individuals to access your content. Last, but not least, current script versions, which are also released for both increased security and for additional features, may need a later version of the Os in order to work correctly and with their full capabilities.