What does porosity in hair refer to?

Porosity in hair specifically refers to the hair's ability to absorb moisture and color. This characteristic is crucial for understanding how different hair types will react to various treatments, such as coloring, moisturizing, and styling products. Hair that is highly porous allows chemicals and moisture to penetrate easily, which can be beneficial for treatment applications but may also lead to issues like excessive dryness or damage over time. Conversely, hair with low porosity is more resistant to moisture absorption, which can affect how well products work and how easily they can be applied.

Understanding porosity is essential for hairstylists and cosmetologists because it helps them tailor their services to meet the individual needs of their clients, ensuring the best possible results while maintaining the health of the hair. The other options relate to different aspects of hair but do not define porosity, making them less relevant to this specific question.