Provide the classification of ligands.

(N/A) Ligands are atoms,molecules,or ions that donate an electron pair to the central metal ion to form a coordination bond. They can be classified based on different criteria:
$1$. On the basis of charge:
- Neutral ligands: $H_2O, NH_3, CO$
- Anionic ligands: $Cl^-, CN^-, OH^-$
- Cationic ligands: $NO^+, NH_2NH_3^+$
$2$. On the basis of denticity (number of donor atoms):
- Monodentate (Unidentate): Ligands with one donor atom (e.g.,$Cl^-, H_2O$)
- Polydentate: Ligands with more than one donor atom (e.g.,$EDTA^{4-}$ is hexadentate)
Special types include:
- Ambidentate ligands: Ligands that can coordinate through two different atoms (e.g.,$SCN^-$ can coordinate through $S$ or $N$)
- Bridging ligands: Ligands that link two metal centers.