What tool is essential for performing hair cutting techniques?

Shears or scissors are essential tools for performing hair cutting techniques because they allow for precision and control when cutting hair. These tools enable stylists to create various styles, textures, and lengths, making them fundamental in both basic and advanced haircutting techniques. The sharp blades of shears and scissors are specifically designed to cut hair cleanly, which helps in achieving a polished finish without causing damage to the ends of the hair.

While other tools like combs are used in conjunction with shears to section hair and guide cuts, they do not perform the cutting action themselves. Brushes are primarily used for styling and detangling rather than cutting, and blow dryers serve to dry and style the hair but are not involved in the cutting process. Therefore, shears or scissors are the indispensable tools that directly facilitate hair cutting.