What tool is commonly used for hair cutting?

In the context of hair cutting, shears or scissors are the primary tools utilized by cosmetologists. They are specifically designed to create clean cuts and precise shapes in the hair. The blades of shears or scissors allow for different cutting techniques, such as point cutting or blunt cutting, which can significantly alter the style and texture of the hair.

In comparison, combs are essential tools, primarily used for sectioning and detangling hair, but they do not cut hair. Razor blades can also be used in cutting techniques; however, they are more specialized tools typically employed for specific styles like texturizing or creating a feathered look. Hair clips are important for holding sections of hair in place during the cutting process, but they do not serve a cutting function. Thus, shears or scissors are the most relevant and essential tool for the actual process of cutting hair.