Which term describes the end of the hair strand that forms a complete circle for a pin curl?

The term that describes the end of the hair strand that forms a complete circle for a pin curl is "circle." In pin curling techniques, the circle is critical as it defines the curl's shape and helps determine the curl's tightness and direction. The circle aspect is the part of the curl that wraps around itself and creates the desired rounded effect.

In contrast, the other terms refer to different concepts within hairstyling. "Cascade" typically relates to a style that creates layers or movement, "wave" refers to the undulating pattern that can be created in the hair, and "volume" denotes the fullness or body of the hairstyle. Each of these plays a significant role in hairstyling but does not specifically describe the circular portion of a pin curl. Understanding these terms enhances your ability to perform different styles and techniques effectively in hairstyling.