In haircutting, what does the term 'elevation' (projection) refer to?

Elevation, also called projection, refers to the angle at which a section of hair is lifted or held away from the head before it is cut. Elevation controls the amount of graduation or layering in a cut: cutting at 0 degrees (no elevation) creates blunt, one-length results, while higher elevations create graduation and layers. Understanding elevation is central to haircutting theory because it determines the shape and structure of the finished cut. The concept is reliably tested on the exam.