Each and every virtual or dedicated hosting machine has its own Os and works independently from the servers of other customers. Updating the Operating system is often ignored, but doing that may have lots of benefits for your sites. The most significant reason to use the latest version is that patches are typically released to fix security holes within the Os code, so if you do not install the updates, you risk people with harmful intentions to take advantage of these holes and to access your content. OS updates are also released for improved functionality of the system in general and for better compatibility with the hardware on the market, which could directly influence the performance of your sites. If the functionality and the security of your scripts is the reason to update them, you could also find out that their most up-to-date versions require an updated Operating System so as to operate effectively, thus keeping the Operating system up-to-date is always a good idea.