Which hair type is characterized by tight curls?

The hair type characterized by tight curls is coily or curly hair. This type is known for having a distinct and tight curl pattern that can range from small spirals to larger curls. Coily or curly hair often has a significant amount of volume and can be coarser compared to other hair types. Understanding this hair type is crucial for barbers, as it requires specific techniques for cutting and styling to maintain the health and aesthetics of the curls.

The other choices represent different hair characteristics. Straight hair, for instance, lacks any curl pattern and is often smooth and sleek. Wavy hair features a softer wave pattern that is not as tight as coily or curly hair, resulting in a more relaxed appearance. Thickness refers to the diameter of individual hair strands rather than the curl pattern, and it can apply to any hair type. Therefore, coily or curly hair is the correct option as it specifically denotes the tight curl characteristic.