If you get a hosting server of your own, it will work independently, so it will have its own Operating System and you can later install server side applications directly or script-driven sites via a hosting Control Panel. Although keeping the Os updated is not always considered a necessity, it can be a quite important task for a number of reasons. A newer Operating system version could have better support for certain hardware, so you may get better performance for the sites and web apps that you install. Your server shall also be more safe because updates typically include security patches which deal with small issues which may permit unauthorized people to access your content. Last, but not least, more recent 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 effectively and with their 100 % capabilities.