I think your confused on terminology.

Clipless pedals are the ones you click into. Clips is short for toe clips which are the cages your put your feet into that are attached to a standard pedal. A standard pedal is called a platform.

Pros and Cons are as Homebrew01 said. I would add you will eventually fall over if you ride clipless long enough. Not a bad fall but simply a come to a stop then tip over. At the same time you might have a higher speed incident where clipless will keep you from crashing.