Strain-Promoted Azide-Alkyne Cycloaddition (SPAAC) is a chemical reaction that allows for the efficient formation of triazoles from azides and alkynes. This reaction is particularly useful because it does not require a catalyst, making it simpler and more straightforward than traditional methods. The process is driven by the strain in cyclic alkynes, which makes them more reactive. SPAAC is widely used in bioorthogonal chemistry, enabling scientists to label biomolecules without interfering with their natural functions. This technique is valuable in various fields, including biotechnology and drug development, as it allows for precise modifications of complex molecules in living systems.