Why do mountaineers wear crampons on steep snow and ice?

In mountaineering, crampons are specialized sets of spikes designed to be strapped onto the soles of boots to prevent slipping on steep surfaces of snow and ice.1

By biting into the surface, these climbing irons provide the necessary traction to make progress possible in conditions where standard boots would be insufficient. Furthermore, on many slopes, the use of crampons eliminates the need for the labor-intensive process of cutting steps into the ice, thereby increasing efficiency and safety for the climber.1