Ascender: A mechanical device that enables a person to climb a rope without letting him or her slip back down.

Belay Device: The climber should always be clipped into a safety line with a person at the other end controlling the tension. If the climber should fall, a belay device is used to stop the fall.

Carabiner: A D-shaped piece of aluminum or steel stock that has a spring-loaded gate that allows rapid attachment to a rope, harness or gear.

Harness: A seated harness is used to balance and stabilize the climber while climbing. A full-body rock climbing harness may be used for children which helps them stay upright when they come off the wall.

Helmet: A specialized helmet for children.

Static Line: A low-stretch rope that usually stretches no more than 3 to 4 percent working elongation. The static line wears better against the teeth of the ascender than do standard ropes.

Top Rope: Top rope technique involves the belayer sitting on a ledge and belaying the person climbing below, or the top rope running from the belayer up through a carabineer and back down to the climber.

Webbing: Flat webbing is called flat because of how the material is constructed; for example, a car's seat belt is flat webbing. Tubular webbing can be described as placing one piece of flat webbing on top of another, with the sides connected and the center hollow.