Every virtual or dedicated hosting machine has its own Os and operates independently from the hosting servers of other clients. Updating the Operating system is often ignored, but doing that may have quite a lot of advantages for your websites. The most significant reason to use the most up-to-date version is that patches are typically released to repair security holes within the Os code, so if you don't install the updates, you risk people with harmful intentions to use these holes and to access your content. OS updates are also released for improved performance of the system overall and for far better compatibility with the hardware on the market, which can immediately affect the functionality of your sites. If the performance and the security of your scripts is the reason to update them, you might also know that their newest versions require an updated Operating System in order to function effectively, consequently keeping the Operating system up-to-date is always a good idea.