The UPS and the diesel generator are two devices for keeping a web server operational in case there are problems with the primary source - an interruption or unstable current that cannot keep the machine working properly, for instance. UPS is an abbreviation for Uninterruptible Power Supply, though it is frequently called Uninterruptible Power Source also. The UPS is, essentially, a highly effective battery that's attached to the hosting server and to the electric power network all of the time, so in case of any blackout, it is already working, which allows the hosting server to continue running without losing any information. The diesel generator is an engine which will power up a whole data center. It needs some time to start working and it is the UPS which provides this time. Those 2 power solutions are a necessity for any facility or service provider that wants to stop info loss and hardware damage resulting from an unexpected power issue.