N-linked glycosylation is the attachment of a sugar molecule (known as glycan) to an amide nitrogen of asparagine (Asn) residue of a protein, giving rise to a glycoprotein. This type of linkage is important for both the structure and function of some eukaryotic proteins. The N-linked glycosylation process occurs in eukaryotes and widely in archaea, but very rarely in eubacteria. The nature of N-linked glycans attached to a glycoprotein is determined by the protein and the cell in which it is expressed. It also varies across species. Different species synthesise different types of N-linked glycan.

Reference
Wiki: N-linked glycosylation