Copper-Catalyzed Azide-Alkyne Cycloaddition (CuAAC) is a chemical reaction that combines an azide and an alkyne to form a triazole compound. This reaction is significant in click chemistry, a term coined by K. Barry Sharpless, which emphasizes simple, efficient, and selective reactions. The presence of a copper catalyst accelerates the reaction, making it more efficient and allowing for milder conditions. CuAAC is widely used in various fields, including bioconjugation, where it helps attach biomolecules for research and therapeutic purposes. Its versatility and reliability have made it a popular tool in organic synthesis, enabling the creation of complex molecules from simpler ones.