The Complexes compounds in which all the ligands are bound to the metal center which are identical to each other are known as homoleptic complexes and the complexes in which the metal atoms or ions are linked with more than one kind of ligands are known as heteroleptic complexes.
$\begin{array}{ll}
{\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right] \mathrm{Cl}_3} & \rightarrow \text { Homoleptic complex } \\
{\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_4 \mathrm{Cl}_2\right]} & \rightarrow \text { Heteroleptic complex } \\
{\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_5 \mathrm{Cl}\right] \mathrm{SO}_4} & \rightarrow \text { Heteroteptic complex } \\
{\left[\mathrm{Co}(\mathrm{ONo})\left(\mathrm{NH}_3\right)_5 \mathrm{Cl}_2\right]} & \rightarrow \text { Heteroleptic complex }
\end{array}$