The UPS and the diesel generator are two means for keeping a server functioning if there are difficulties with the primary power source - an outage or unstable current that can't keep the hosting server functioning properly, for example. UPS is an abbreviation for Uninterruptible Power Supply, although it is frequently called Uninterruptible Power Source as well. The UPS is, in simple terms, a highly effective battery that's connected to the web server and to the power network consistently, so in case of any interruption, it's already operating, which allows the server to continue doing the job without losing any information. The diesel generator is an engine that will power up an entire data center. It does take some time to start working and it's the UPS that gives it that time. These 2 power solutions are a necessity for any facility or provider that wants to stop information loss and hardware damage as a result of an unexpected electric power problem.