Linus does a great job of explaining the basics of a UPS (uninterruptible power supply) in this video, check it out and learn why its essential for any computer user.
I wanted to take the time to express the importance of an UPS. A UPS does much more than just give you battery backup time to shut down. A good UPS also provides clean power and protects from brown outs to help your computer remain reliable.
Comment below if you have any questions.