Every virtual or dedicated server has its own Operating System and works independently from the servers of other customers. Updating the OS is usually overlooked, but doing that may have a wide range of advantages for your websites. The most important reason to use the latest version is that patches are usually released to deal with security holes in the Os code, so if you do not install the updates, you risk individuals with harmful intentions to use these holes and to gain access to your content. Operating system updates are also released for enhanced efficiency of the system in general and for far better compatibility with the hardware available on the market, which can immediately influence the functionality of your sites. If the efficiency 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 operate effectively, therefore keeping the OS up-to-date is always recommended.