If you're a regular climber, whether at the climbing wall or crag you will probably have come across bolt protection. All lead climbing on climbing walls is protected with a form of fixed protection known as bolts. Strictly speaking the bolt is made up of a hanger - which you clip your quickdraw into and the bolt itself which fixes the hanger to the wall or cliff face.
Bolts are also used to protect rock climbing routes. Climbing bolt protected routes is known as Sport Climbing and is very popular all over the world on all types of rock. Bolts allow blank sections of rock to climbed in relative safety if placed correctly.
In the UK bolts are only used as protection in certain specific areas and are strongly opposed in bolt free areas. If a bolt is placed as protection on a route in a bolt free area it would normally be removed very quickly.
Holes for bolts can be made with a hand drill but this is very time consuming and most bolts, especially for Sport Climbing are placed with a cordless power drill whilst hanging on an abseil rope. bolts are also used as abseil anchors when canyoneering and caving and they are also widely used in many Rope Access situations.