What type of haircut requires knowledge of layering?

A graduated haircut requires knowledge of layering as it involves cutting hair to create a soft, blended effect where the hair transitions from shorter lengths at the back and sides to longer lengths on the top. This technique relies heavily on understanding how to layer hair, allowing the stylist to achieve the desired volume and shape throughout the cut.

In a graduated haircut, the layers not only help with aesthetics but also enhance the hair's movement and texture. The stylist must skillfully manipulate the angle and tension of the cut to create the graduation, which gives the overall hairstyle depth and dimension.

The other haircuts listed do not involve layering to the same extent. A buzz cut features uniform length and does not require any layering techniques, while a flat top haircut emphasizes a consistent length across the top and does not involve the blending of layers. A crew cut is also characterized by being cut uniformly short, lacking the layer structure that makes graduated haircuts distinctive.