A gable is the generally triangular portion of a wall between the edges of a sloping roof. The shape of the gable and how it is detailed depends on the structural system used (which is often related to climate and availability of materials) and aesthetic concerns. Thus the type of roof enclosing the volume dictates the shape of the gable. A gable wall or gable end more commonly refers to the entire wall, including the gable and the wall below it.
A gable end is an architectural term which is used to refer to the vertically triangular wall between the sloping roofs of a gable building. The gable's shape will depend on the structural system that is in use.