What type of haircut involves gradually shortening the hair at the sides and back while leaving length on top?

The type of haircut that involves gradually shortening the hair at the sides and back while leaving length on top is known as a taper. In this style, the hair is cut short at the bottom and gradually increases in length as it moves up towards the top. This creates a smooth transition from the shorter sides and back to the longer hair on top, providing a clean and polished look that can be styled in various ways.

A taper typically offers a more subtle gradient compared to fades, where the transition is often more pronounced and can blend into the skin. Layered cuts focus more on texturizing and adding volume to the hair rather than the gradual shortening aspect. An undercut involves cutting the sides very short or shaving them entirely while leaving the top long, which does not align with the description of gradually shortening the hair.