Spectrophotometry is a scientific technique used to measure how much light a substance absorbs at different wavelengths. It works by passing light through a sample and detecting the intensity of light that emerges. The amount of light absorbed can provide valuable information about the concentration and properties of the substance being analyzed. This method is widely used in various fields, including chemistry, biology, and environmental science. By analyzing the absorption spectrum, researchers can identify specific compounds and monitor changes in concentration over time, making it a crucial tool for both research and quality control in laboratories.