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A glycoside forms when the anomeric hydroxyl group of a sugar reacts with an alcohol or amine. The bond can be made through acid-catalyzed chemical synthesis or, in biological pathways, by glycosyltransferases using activated nucleotide-sugar donors. Once formed, the bond fixes the anomeric carbon in an α or β configuration, preventing mutarotation and removing the sugar’s reducing power. Glycosides may be O-linked or N-linked, and their names and linkage positions describe their structure. Specific linkages help determine the properties of carbohydrates such as cellulose, glycogen, and lactose. Glycoside formation and breakdown also matter in biomolecule glycosylation, medicines, and disorders involving carbohydrate metabolism.