Fluorescent dyes are a class of chemical compounds that emit visible light when exposed to ultraviolet or visible light. These dyes are commonly used in a variety of applications, including biological imaging, medical diagnostics, material science, and forensics. They are characterized by their ability to absorb light at a specific wavelength and emit light at a longer wavelength, resulting in a bright and colorful fluorescence. Fluorescent dyes are often used in combination with fluorescent microscopy techniques to visualize and study biological processes at the cellular and molecular levels. Additionally, they are used as labeling agents to track and monitor molecules in complex biological systems.