A batten is most commonly a strip of solid material, historically wood but can also be of plastic, metal, or fiberglass. Battens are variously used in construction, sailing, and other fields.
Board and batten siding on a chapel named the Wooden Church (Biserica de lemn) in Zvoriștea, Romania
Roofing battens or laths are the light colored strips on the Hillsgrove Covered Bridge, Pennsylvania, U.S.A.
Board-and-batten with bamboo battens
A traditional Japanese maira-do, a batten door
A rafter is one of a series of sloped structural members such as steel beams that extend from the ridge or hip to the wall plate, downslope perimeter or eave, and that are designed to support the roof
Common rafters without collar beams form most of this roof. There is not always a ridge board or beam where the rafter tops meet. Under the midsections of the rafters are purlins which support the common rafters and are supported by principal rafters. This roof ends in an octagonal hip.
Rafter and tie-beam joints (Carpentry and Joinery, 1925)