Every virtual or dedicated hosting machine has its own Os and operates independently from the hosting servers of other clients. Updating the OS is frequently neglected, but doing that might have a wide range of advantages for your websites. The most essential reason to use the most recent version is that patches are typically released to deal with security holes in the Os code, so if you don't install the updates, you risk individuals with harmful intentions to exploit these holes and to gain access to your content. OS updates are also released for much better efficiency of the system overall and for much better compatibility with the hardware available on the market, which can directly impact the functionality of your websites. If the functionality and the security of your scripts is the reason to update them, you could also find out that their newest versions require an updated Operating System so as to function effectively, so keeping the OS up-to-date is always a wise idea.