A spectrometer is an instrument used for measuring properties of light over a specific portion of the electromagnetic spectrum. These properties can include intensity, wavelength, and polarization of light. Spectrometers are commonly used in various fields such as chemistry, physics, astronomy, and environmental science to analyze the composition of materials, determine the chemical structure of molecules, and study the properties of celestial objects. They work by dispersing light into its component wavelengths using a prism or diffraction grating, and then measuring the intensity of each wavelength using detectors. Spectrometers come in different types such as optical spectrometers, mass spectrometers, and infrared spectrometers, each tailored for specific applications.