The UPS and the diesel generator are 2 devices for keeping a web server functional in case there are problems with the primary power supply - a disruption or unstable current that cannot keep the hosting server working properly, for instance. UPS is an abbreviation for Uninterruptible Power Supply, though it is frequently called Uninterruptible Power Source also. The UPS is, basically, a highly effective battery that is connected to the server and to the electricity network at all times, so in case there is any disruption, it is already operating, which allows the server to continue doing the job without losing any info. The diesel generator is an engine which will power up an entire data center. It needs some time to begin working and it's the UPS which gives it this time. These 2 power solutions are a requirement for any facility or provider that wants to stop info loss and hardware damage as a consequence of an unexpected electric power problem.