I don't really know. They are also used in the chambers of Congress as well as at auctions. They are for keeping order as well signifying an official end of a proceeding. British courts do not use them but in their history courts did use them for unruly parties and audiences. Someone gave me a gavel years ago. I don't know where it is at this moment though. I read that today the gavel is not used in American court rooms. That is incorrect.