Clove Hitch
The clove hitch, along with the bowline and the sheet bend, is often considered one of the most essential knots. It consists of two identical half hitches made successively around an object.
It is most effective when used as a crossing knot. Although it can be used as a binding knot, it is not particularly secure in that role. Because it passes around an object in only one direction, it puts very little strain on the rope fibers.