A spectrophotometer is an analytical instrument used to measure the intensity of light at different wavelengths, typically in the ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum. It works by passing light through a sample and detecting the amount of light absorbed or transmitted, which can provide information about the sample's concentration, composition, and properties. Spectrophotometers are widely used in various fields, including chemistry, Biology, and environmental science, for applications like quantitative analysis and quality control.