The UPS and the diesel generator are two means for keeping a server operational in case there are troubles with the primary power source - an interruption or unreliable current that can't keep the hosting server functional, for instance. UPS is an abbreviation for Uninterruptible Power Supply, although it can often be referred to as Uninterruptible Power Source also. The UPS is, essentially, an effective battery that is attached to the web server and to the power network constantly, so if there is any disruption, it is already working, that permits the hosting server to carry on running without losing any data. The diesel generator is an engine that can power up the entire data center. It does take some time to begin working and it is the UPS that gives it that time. Those 2 power solutions are an absolute necessity for any facility or provider that wants to stop info loss and hardware damage as a consequence of an unexpected electric power issue.