A climbing shoe is specifically designed and worn for climbing. The shoe is covered in a rubber layer that gives a very hig level of friction with the climbing surface. Usually, the shoes are only a few millimetres thick and have a very tight fit around the feet for stability.
High performance shoes are soled with a special vulcanized rubber that becomes flexible as it gets warm due to friction. This vastly increases the surface area between the shoe and the rock thus providing a better grip for the climber. The rubber extends up the sides of the shoes for still more gripping opportunity, though as a very thin layer since it does not bear any loads. The rubber being relatively soft, it is prone to being worn away by rough rock surfaces, and it is not unusual for a favourite pair to be resoled periodically; this may be done by a service, or with a kit.