From Wikipedia:
Sand animation, also known as sand art, is a term which has two meanings. It is the name given to a style of live performance art and to a type of animation. In the former, an artist creates a series of images using sand, a process which is achieved by applying sand to a surface and then rendering images by drawing lines and figures in the sand with one’s hands. A sand animation performer will often use the aid of an overhead projector or lightbox (similar to one used by photographers to view translucent films). In the latter, animators move around sand on a backlighted or frontlighted piece of glass to create each frame for their animated films.
