A tattoo is a mark made by putting ink into the skin. Tattoos may be made on human or animal skin. Tattoos on humans are a type of body modification (a way of changing the body), but tattoos on animals are most often used for identification. People sometimes get tattoos to show that they belong to a gang or culture group.
People get tattoos in tattoo parlors. Getting a tattoo is painful, although some people have more pain than others, and some body parts are more painful to tattoo than others. Most tattoos today are created using an electric tattoo machine, which uses needles to put ink into the body.