These two types of bonding are very similar and so can easily be confused however this question specifically wants the difference between them. Covalent bonding occurs when a pair of nuclei share a pair of electrons with one electron being donated by each atom. In dative covalent bonding the same principle of sharing electrons between two nuclei applies except in this case both of the electrons involved in bonding are donated by one of the atoms. i.e. one atom doesn't donate any bonding electrons but the other donates both electrons required for bonding.