UPS is an abbreviation for Uninterruptible Power Supply or Uninterruptible Power Source. It's a battery that is used to power a computer or a hosting server to avoid the loss of information if the main power supply fails for some reason or becomes unsafe. A diesel generator practically self-explanatory. UPSs and generators are used as a backup in data centers to back up the power supply and to ensure the constant operation of all of the machines located there. As the UPS runs all the time, it offers the desired power for the machines to remain operational until the generator starts and takes over. Using this type of a backup is a must for any data center or provider that wants to keep their hardware and data intact in the case of a power surge or outage, due to the fact that it gives them plenty of time to react until the issue is resolved and the main power supply is restored.