Knots

A knot is a method of fastening that involves tying a rope, cord, or similar flexible strand. Knots are used to secure a load, join lines, or create a loop, and rely on the geometry of the knot and the friction of the fibers to hold under load.

Knots are commonly categorized by purpose: bends, which join two ends; hitches, which attach a rope to an object or to another rope; loops, which form a fixed or adjustable loop; and stopper knots, used to prevent a line from slipping through openings.

Several knots are widely known for everyday or specialized use. The bowline creates a fixed loop that does not tighten under load; the square knot (reef knot) joins two rope ends; the figure-eight knot provides a strong stopper or loop; the clove hitch attaches to posts or spars; the overhand knot is the simplest stopper knot.

Knots are used in sailing, climbing, rescue, fishing, camping, and theater rigging, among other fields. The choice of knot affects strength, ease of tying and untying, security under movement, and how well the rope can be freed after loading.

In mathematics, knot theory studies abstract closed loops independent of material, contrasting with practical rope knots. Historically, knot tying has been a practical skill in nautical and outdoor traditions and continues to be taught for safety and versatility.