If you get a hosting server of your own, it will operate independently, so it will have its own Os and you can later install server side applications directly or script-driven internet sites via a hosting Cp. Though keeping the Os updated isn't always considered an absolute necessity, it can be a quite important task for a variety of reasons. A newer OS version may have better support for certain hardware, so you might get better performance for the websites and web applications which you install. Your server shall also be more protected as updates typically include security patches which deal with small problems that may permit unauthorized individuals to access your content. Last, but not least, more recent script versions, which are also released for both increased security and for additional features, might require a later version of the Os in order to work properly and with their full capabilities.