to my knowledge a regular pedal you would find on most bikes will be called a platform, Clipless refers to the fact that the way people used to attach their feet to the pedals was through toe-clips, or clips. A plastic or metal strap that went around your foot longways, from the bottom over the toe and then was tightened with a strap. So clipless refers to pedals that you attach your feet to the bike with, but without clips. You snap in and twist out of clipless pedals and they take special shoes.
It's cheating because your feet are completely attached to the pedal so there is a lot less skill involved in using your feet to lift up your bike, all you have to do is jump and lift your legs while someone without clipless would have to readjust their feet or use an entirely different technique.