Board and batten, or board-and-batten, describes a type of exterior siding or interior paneling that has alternating wide boards and narrow wooden strips, called battens. The boards are usually (but not always) one foot wide. The boards may be placed horizontally or vertically. The battens are usually (but not always) about 1/2 inch wide. These battens are placed over the seams between the boards.
Reverse board and batten has very narrow boards with wide battens installed over the seams.
Board-and-batten siding is sometimes called barn-siding, because many barns in North America are constructed with board and batten.
The words board and batten are hyphenated when used as an adjective, but not hyphenated when used alone. For example, we say: "My home has board-and-batten siding. Our builder constructed the house using board and batten."