Coils are loops or spirals of material, often made from wire or other flexible substances. They are commonly used in various applications, such as in electrical devices, springs, and heating elements. The shape of a coil allows it to store energy, create magnetic fields, or provide resistance, depending on its design and purpose. In electrical engineering, coils are essential components in devices like transformers and inductors. When an electric current passes through a coil, it generates a magnetic field, which can influence nearby circuits. This principle is fundamental to the operation of many technologies, including motors, generators, and wireless charging systems.