What a knot is and how knots are classified

A knot is an intentional complication in cordage, practical or decorative or both. Practical knots are classified by what they do rather than how they look. Four broad functional groups cover almost everything a person ties in the field: hitches, bends, loop knots, and splices.

A hitch fastens a rope to another object — a post, ring, spar, or another rope used as the anchor. A bend joins two ropes end to end. A loop knot puts a fixed or adjustable loop somewhere along the rope. A splice is any multi-strand knot, including bends and loops, formed by interweaving strands rather than tying. The word knot in its strictest sense also means a stopper or knob at the end of a rope, used to keep that end from slipping through a grommet, eye, or block.

Knots have been studied and used since antiquity. Their topological intricacy is the basis of knot theory in mathematics, but the practical tradition is older and very different in spirit: a sailor or climber cares about whether the knot is easy to tie under load, easy to untie after load, secure under cyclic motion, and appropriate to the rope and the task.

This pack groups entries by function: foundations, hitches, loops, bends, lashings, friction hitches, and stoppers. The same physical knot sometimes belongs in more than one category — the reef knot, for example, is a binding knot that has been misused as a bend for centuries — and the cross-references in each entry note the related forms.