A tattoo machine is a hand-held device generally used to create a tattoo, a permanent marking of the skin with indelible ink. Modern tattoo machines use electromagnetic coils to move an armature bar up and down. Connected to the armature bar is a barred needle grouping that pushes ink into the skin. Tattoo artists generally use the term "machine", or even "iron", to refer to their equipment. The word "gun" is often used but many tattoo professionals dislike it. In addition to "coiled" tattoo machine there are also Rotary Tattoo Machines, which are powered by regulated motors rather than electromagnetic coils.