Every virtual or dedicated server has its own Operating System and functions separately from the hosting servers of other customers. Updating the Operating system is often neglected, but doing that might have a wide range of benefits for your sites. The most important reason to use the most recent version is that patches are usually released to repair security holes inside the Os code, so if you don't install the updates, you risk individuals with malicious intentions to take advantage of these holes and to access your content. Operating system updates are also released for enhanced functionality of the system in general and for much better compatibility with the hardware available on the market, which can directly affect the efficiency of your websites. If the functionality and the security of your scripts is the reason to update them, you might also discover that their latest versions require an updated Operating System to be able to operate properly, so keeping the OS up-to-date is always recommended.