Each virtual or dedicated hosting machine has its own Os and operates separately from the servers of other clients. Updating the OS is usually neglected, but doing that could have quite a lot of benefits for your sites. The most essential reason to use the newest version is that patches are typically released to fix security holes inside the Operating System code, so if you do not install the updates, you risk people with malicious intentions to take advantage of these holes and to get access to your content. OS updates are also released for much better functionality of the system in general and for better compatibility with the hardware on the market, which could immediately influence the efficiency of your websites. If the performance and the security of your scripts is the reason to update them, you may also discover that their most recent versions require an updated Operating System so as to work effectively, consequently keeping the OS up-to-date is always recommended.