Absorption spectroscopy is a technique used to analyze the interaction between light and matter. When light passes through a sample, certain wavelengths are absorbed by the material, depending on its molecular structure. This absorption creates a spectrum that can be measured, revealing information about the sample's composition and concentration. The resulting spectrum displays peaks at specific wavelengths, indicating the presence of different molecules or elements. By comparing these peaks to known standards, scientists can identify substances and quantify their amounts. This method is widely used in fields like chemistry, biology, and environmental science for various applications, including quality control and research.