The pH level is a measure of how acidic or basic a solution is, ranging from 0 to 14. A pH of 7 is considered neutral, meaning it is neither acidic nor basic. Values below 7 indicate acidity, while values above 7 indicate alkalinity. The pH level is important in various fields, including chemistry, biology, and environmental science, as it affects chemical reactions and biological processes. pH levels can be measured using pH indicators or pH meters. For example, litmus paper changes color depending on the acidity or alkalinity of a solution. Maintaining the right pH level is crucial for agriculture, aquatic life, and even human health, as it influences nutrient availability and organism survival.