(a) Unidentate ligands: these are ligands with one donor site. Example Cl^–, NH₃

(b) Bidentate – these are ligands with two donor sites.
Example – Ethane-1,2-diamine, Oxalate ion ( C₂O₄^2- )

(c) Ambidentate ligands: these are ligands that fasten themselves to the central metal ion/ atom via two different atoms.
Example NO^–₂or ONO^–, CN^– or NC^–