What is the primary purpose of a haircut?

The primary purpose of a haircut is to change the shape and length of the hair. Haircuts are designed to alter the appearance of hair by removing length, creating layers, or shaping the overall style. This transformation can dramatically affect how a person looks and how they express their personal style. While maintaining an existing style is certainly part of what haircuts can achieve, the fundamental aspect of a haircut is the actual change to the hair's shape and length. This allows for versatility in styling and helps individuals achieve specific looks according to their preferences or current trends.

Changing hair color, while important in hairstyling, does not relate to cutting hair and its direct impact on length and shape. Similarly, adding volume is usually achieved through different styling techniques and products rather than through the act of cutting hair itself. Therefore, focusing on the reshaping and shortening of hair makes option C the most accurate representation of a haircut's primary purpose.