A coil tattoo machine is a type of tattooing device that uses electromagnetic coils to create the needle's movement. It consists of a frame, coils, a power supply, and a needle. When electricity flows through the coils, they generate a magnetic field that causes the needle to move up and down, allowing ink to be injected into the skin. These machines are known for their reliability and ability to produce clean lines and vibrant colors. Artists often prefer coil machines for their versatility, as they can be adjusted for different styles of tattooing, including shading and lining.