A mask is an object normally worn on the face, typically for protection, disguise, performance, or entertainment. Masks have been used since antiquity for both ceremonial and practical purposes. They are usually worn on the face, although they may also be positioned for effect elsewhere on the wearer's body.
This stone mask from the pre-ceramic neolithic period dates to 7000 BC and is probably the oldest mask in the world
Here are some helpful video tutorials.