If you get a hosting server of your own, it will run independently, so it'll have its own Operating System and you'll be able to later install server side programs directly or script-driven websites through a hosting Control Panel. While keeping the Operating System updated isn't always considered a necessity, it can be a rather important task for several reasons. A newer Operating system version could have better support for certain hardware, so you may get better performance for the internet sites and web applications which you install. Your server shall also be more secure because updates often include security patches that resolve small issues that may enable unauthorized people to access your content. Last, but not least, newer script versions, which are also released for both enhanced security and for additional features, might require a later version of the Os in order to work correctly and with their full capabilities.