What does pH measure in relation to solutions?

pH measures the acid-alkaline balance of a solution, which reflects its level of acidity or alkalinity on a scale ranging from 0 to 14. A pH value below 7 indicates an acidic solution, a pH of 7 denotes a neutral solution, and a pH above 7 suggests alkalinity. This measurement is crucial in hair coloring and treatments, as different products may require specific pH levels to function effectively. For example, hair color formulations often rely on an appropriate pH to ensure proper color penetration and longevity in the hair shaft. Understanding the pH balance allows haircolorists to make informed decisions about product selection and chemical processes, thereby achieving optimal results for their clients.