Click chemistry refers to a set of synthetic methods that are used to quickly and reliably construct diverse molecular architectures. The term was coined by Nobel laureate K. Barry Sharpless and refers to the fact that these reactions are highly reliable, specific, and efficient - like clicking together two Lego blocks. Click chemistry has become widely used in organic chemistry, medicinal chemistry, materials science, and bioconjugation due to its ease of use and versatility. Some common examples of click reactions include the Huisgen 1,3-dipolar cycloaddition, copper-catalyzed azide-alkyne cycloaddition, and thiol-ene reactions. Click chemistry has revolutionized the way chemical compounds are synthesized and has led to numerous advancements in drug discovery, materials science, and other fields.