Explain the terms 'Coordination Entity' and 'Central Atom/Ion' in the context of coordination compounds.

(N/A) Coordination Entity: $A$ coordination entity constitutes a central metal atom or ion bonded to a fixed number of ions or molecules.
Example: In $\left[ CoCl_3(NH_3)_3 \right]$,the cobalt ion is surrounded by three ammonia molecules and three chloride ions.
Central Atom/Ion: The atom or ion to which a fixed number of ions or groups are bound in a definite geometrical arrangement around it in a coordination entity is called the central atom or ion.
Example: In $\left[ CoCl_3(NH_3)_3 \right]$,the central metal ion is $Co^{3+}$,which acts as a Lewis acid.