N- and O-glycosylation represent the predominant protein glycoforms. N-glycans feature a conserved GlcNAc₂Man₃ core attached to asparagine (Asn) within Asn-X-Ser/Thr sequons. Glycan structural diversity stems from non-template-driven biosynthesis, expressed via diverse monosaccharide arrangements, linkage variations, branching architectures, and isomeric configurations.