Each virtual or dedicated server has its own Operating System and works separately from the hosting servers of other customers. Updating the OS is usually ignored, but doing that might have a wide range of advantages for your internet sites. The most important reason to employ the most up-to-date version is that patches are typically released to fix security holes in the Os code, so if you don't install the updates, you risk people with malicious intentions to exploit these holes and to access your content. OS updates are also released for much better performance of the system in general and for much better compatibility with the hardware available on the market, which could immediately influence the functionality of your internet sites. If the performance and the security of your scripts is the reason to update them, you may also find out that their latest versions require an updated Operating System to be able to work properly, consequently keeping the OS up-to-date is always a wise idea.