A wedge or stacked haircut has shorter hair that lies on top of longer hair, which creates fullness. The stacked bob is a classic example of a wedge haircut. However, the term "wedge" actually refers to a technique that involves cutting hair at various elevations to create volume.
There are several variations to the wedge haircut, depending on where the technique is used on the head. If hair is stacked at the bottom, a bob style is created. If hair is stacked at the occipital bone, the bony protrusion on the back of the head, a tapered style is created.