The pH scale is a numerical scale that measures how acidic or basic a solution is. It ranges from 0 to 14, where a pH of 7 is considered neutral, meaning it is neither acidic nor basic. Values below 7 indicate acidity, with lower numbers representing stronger acids, while values above 7 indicate alkalinity, with higher numbers representing stronger bases. The pH scale is important in various fields, including chemistry, biology, and environmental science. For example, soil pH affects plant growth, and water pH can influence aquatic life. Understanding pH helps in managing these systems effectively.