A knot is created when long, bendable items such as ropes, strings, wires, chains and other materials become intertwined. Though a knot can technically be created by tying multiple materials together, knots typically involve just one solid line that is intertwined. The main function of knots is to provide security and strength, while preventing a line from slipping or sliding.
Common types of knots include the fisherman's knot, which is used to tie hooks to fishing lines; the timber hitch, which attaches a rope to a piece of wood; the alpine butterfly, which produces a loop that allows load-bearing hooks to clasp to it; the constrictor knot, which can bind to other fibers or materials; the sheep shank, which secures heavy loads to the device pulling or towing them; the figure-eight knot, which is commonly used in sailing and rock climbing; the bowline, which fastens or holds items in place; and the taut-line hitch, which secures lines that are under heavy tension.
A knot has a few key parts. The loop is the circle that forms when you're creating the knot. The working end, sometimes referred to as the live end, is the end of the material that is being used to make the knot. The standing part is the part of the material that exists between the knot and its standing end, or the end that wasn't actively used to create the knot. The bight is the center part of the material used to make the knot.
Knots are commonly seen in many modern-day activities and cultures. Celtic knots are decorative patterns that are seen throughout the Irish and Christian cultures. Many knots are utilized on sailboats in order to control the boat's sails and assist in its anchoring, docking and mooring. Rock climbers use knots to tie their climbing ropes to their safety harnesses. Knots are also created involuntarily all the time when one or more free-flowing materials become entangled. Strands of hair, electrical wires or cords, and chains, including industrial chains and delicate necklace chains, can all become knotted very easily.
Some knots are so effective that they are difficult, if not impossible, to undo once they're created. The constrictor and double constrictor knots are very difficult to separate, as are boa knots, carrick bends, the ringknot, fisherman's knot, overhand, loop knot and grapevine knots. Even some of the looser, more standard knots can become stubborn and hard to untie if they are pulled too taut or have too much weight placed on their lines.