The collective panels used to decorate or cover a wall are called paneling. If you have really dark wood paneling in your house, you can try to lighten it up with paint, but use a primer first because the dark stain tends to show through paint.
Although paneling usually refers to wood covering on a wall, the word paneling is derived from panel, which originally referred to cloth. Panel is an Old French word meaning a piece of cloth, and that word is from the Latin word pannus, which has the same meaning. Today, there are many different types of wood paneling, including board and batten, bead board, tongue and groove, and flat or raised panels.