A tattoo gun is a handheld device used by tattoo artists to create permanent designs on the skin. It works by rapidly puncturing the skin with needles that inject ink into the dermis layer. The device typically consists of a motor, a needle, and an ink reservoir, allowing for precise control over the tattooing process. There are different types of tattoo guns, including rotary and coil machines. Rotary machines use a motor to drive the needle, while coil machines use electromagnetic coils. Both types have their own advantages and are chosen based on the artist's preference and the desired tattoo style.