Any series of narrow strips of wood, bamboo or metal that are fixed in parallel lines. For bed bases they run across the bed, so that the natural spring is created along the length of the bed. With blinds and louvres they run horizontally so that they can be tipped, folded or rolled to control light and air.
Blind slats can usually be adjusted to lie flat or turn through 180º to provide all angles of breeze, light filtering and closure. In doors, windows or shutters, the louvres may be flexible but most are fixed in such a way as to provide screening, light without glare and allow the rain to run off.