Bouldering involves routes that are close to the ground without the need for a harness or a rope. A thick crash pad or padded flooring provides some protective for falls, but falling the wrong why can still lead to certain injuries.
Bouldering is a great way to build skill because you can focus solely on using your strength and balance to keep yourself on the wall. Novices appreciate the simplicity of it; skilled climbers like the challenge of more difficult routes.