A knot diagram is a visual representation of a knot, typically drawn on a flat surface. It consists of a series of curves that represent the strands of the knot, with crossings indicated by over and under relationships. Knot diagrams help in understanding the structure and properties of knots, making them easier to analyze and classify. These diagrams are essential in the field of topology, a branch of mathematics that studies the properties of space. Knot diagrams can also be used in practical applications, such as sailing, climbing, and crafting, where understanding knots is crucial for safety and functionality.