They are used with socket for torquing purpose work where more accuracy is not required as it is one of uncontrolled way of torquing.
A ratchet handles snaps into one end of an attachment by methods for a square-drive connector. The opposite end of the attachment fits over a fastener. An instrument in the ratchet enables the handle to draw in and fix a latch when you swing it a clockwise way, however, turn uninhibitedly when you swing it counter clockwise. A switch on the ratchet turns around the activities to loosen fasteners.