What characteristic distinguishes vellus hair from terminal hair?

Vellus hair is typically characterized by being finer, shorter, and lighter in color compared to terminal hair. The primary distinction lies in color and thickness, as vellus hair is often soft and barely noticeable, whereas terminal hair is thicker, darker, and more robust. This characteristic is crucial in understanding the different types of hair on the human body, as it highlights the varying roles and appearances of these hair types in different areas.

The other factors, such as length and growth rate, as well as location on the body, can contribute to distinguishing between vellus and terminal hair; however, color and thickness are the most straightforward and essential characteristics that differentiate the two types. Therefore, it's important to recognize that while other aspects may differ, the most direct characteristics that set vellus hair apart from terminal hair are indeed color and thickness.