Define "porosity" in hair.

Porosity in hair refers specifically to the hair's ability to absorb moisture. This property is crucial for hair care because it influences how well hair can retain hydration and product. High porosity hair tends to absorb moisture quickly but may also lose it just as fast, sometimes leading to dryness and frizz. Conversely, low porosity hair has a more tightly packed cuticle layer, making it harder for moisture and products to penetrate, often necessitating different hair care approaches.

Understanding porosity is essential for choosing appropriate products and treatments that cater to individual hair needs. For instance, those with highly porous hair might benefit from deeper conditioning treatments to help retain moisture, while those with low porosity hair might need lighter products that won't weigh their hair down. This knowledge allows hairstylists and clients to better address specific hair concerns and maintain healthy hair.