The term "helical" refers to a shape or structure that resembles a spiral or a coil. It is often used to describe the form of a helix, which is a three-dimensional curve that winds around a central axis. Helical shapes can be found in various natural and man-made objects, such as DNA, springs, and screws. In mathematics and engineering, helical structures are important for understanding motion and design. For example, a helical gear allows for smooth transmission of power between shafts that are not parallel. The helical shape can also enhance strength and efficiency in various applications, making it a key concept in many fields.