pH strips are simple tools used to measure the acidity or alkalinity of a solution. They are made of special paper that changes color when dipped into a liquid. Each color corresponds to a specific pH value on a scale that ranges from 0 to 14, with 7 being neutral. Values below 7 indicate acidity, while values above 7 indicate alkalinity. These strips are commonly used in various fields, including chemistry, biology, and even gardening. They help users quickly assess the pH level of substances like soil, water, or food, making them valuable for both professionals and hobbyists.