Aspirin, also known as acetylsalicylic acid (abbreviated ASA), is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. Aspirin also has an antiplatelet effect by inhibiting the production of thromboxane, which under normal circumstances binds platelet molecules together to create a patch over damaged walls of blood vessels.
It is the salicylate ester of acetic acid; in fact, its synthesis is classified as an esterification reaction: