Every virtual or dedicated hosting server has its own Operating System and operates independently from the hosting machines of other customers. Updating the Operating system is often ignored, but doing that may have quite a lot of benefits for your sites. The most important reason to use the most up-to-date version is that patches are typically released to repair security holes inside the Os code, so if you do not install the updates, you risk people with malicious intentions to exploit these holes and to get access to your content. Operating system updates are also released for improved functionality of the system overall and for much better compatibility with the hardware on the market, which could immediately affect the functionality of your websites. If the functionality and the security of your scripts is the reason to update them, you might also discover that their most up-to-date versions require an updated Operating System to be able to work effectively, thus keeping the OS up-to-date is always wise.
