What type of knot is the overhand knot?

The overhand knot is classified as a stopper knot. Its primary function is to prevent the end of a rope from unraveling or slipping through other knots or equipment. This simple knot is formed by creating a loop with the rope and then passing the free end through that loop, resulting in a structure that effectively adds bulk to the end of the rope. This makes it useful in various applications where securing the end is crucial, such as when tying off fishing lines or securing a rope within a pulley system.

In contrast, while the other options are different types of knots, they do not fit the characteristics or uses of the overhand knot. A square knot is designed for joining two lengths of rope and is not intended to act as a stopper. An inline knot refers to knots tied in a straight line, which does not describe the overhand knot's function. An end-to-end knot specifically joins two ropes together, which is distinct from the role of the overhand knot. Therefore, identifying the overhand knot as a stopper knot highlights its important role in enhancing safety and functionality in rope rescue practices.