Each virtual or dedicated hosting machine has its own Os and functions independently from the hosting servers of other clients. Updating the OS is often neglected, but doing that may have a wide range of benefits for your sites. The most significant reason to employ the latest version is that patches are typically released to deal with security holes inside the Operating System code, so if you don't install the updates, you risk people with malicious intentions to exploit these holes and to gain access to your content. OS updates are also released for much better performance of the system overall and for better compatibility with the hardware available on the market, which could instantly impact the performance of your sites. If the efficiency and the security of your scripts is the reason to update them, you may also know that their latest versions require an updated Operating System to be able to function effectively, therefore keeping the OS up-to-date is always a wise idea.