A knot diagram is a visual representation of a knot, showing how the strands of rope or string interweave. These diagrams use lines to depict the knot's structure, with crossings marked to indicate where one strand goes over or under another. Knot diagrams help in understanding and analyzing the properties of knots in various fields, including mathematics and crafts. Knot diagrams are essential in the study of knot theory, a branch of topology that explores the mathematical properties of knots. They can also be used in practical applications, such as sailing, climbing, and crafting, where understanding knots is crucial for safety and functionality.