The UPS and the diesel generator are 2 instruments for keeping a web server functional in case there are difficulties with the primary power source - an interruption or unreliable current which cannot keep the web server working properly, for instance. UPS is an abbreviation for Uninterruptible Power Supply, even though it is sometimes referred to as Uninterruptible Power Source too. The UPS is, in simple terms, a powerful battery which is attached to the hosting server and to the power network constantly, so if there is any disturbance, it is already functioning, which allows the hosting server to keep on operating without losing any information. The diesel generator is an engine which can power up an entire data center. It needs some time to begin working and it's the UPS that provides that time. These two power solutions are fundamental for any facility or provider that wants to avoid information loss and hardware damage caused by an unexpected power problem.