Clapboard

A small board that displays information for each shot in a movie or documentary and is filmed at the beginning of a take. The board typically contains the working title, the names of the director, editor and director of photography, the scene and take numbers and the date and time. On the top of the clapboard is a hinged wooden stick (called a clapstick or clapper) which is often clapped to provide audio/visual synchronization of the sound with the picture during editing. Electronic clappers and synchronization are also used instead of the old-fashioned clapboard. Also called Clapper. [Source: Filmsite.org]