Diastereomers and enantiomers are both two types of stereoisomers. The difference between diastereomers and enantiomers is that diastereomers of a molecule are not the spitting image of each other.
Enantiomers, however, are succinctly the spitting image of one another. Enantiomers have similar physical and chemical properties, with the exemption of their different optical properties toward polarized light. Diastereomers can possess several molecules, although Diastereomers have different physical and chemical properties.
Enantiomers occur in segments. While enantiomers cannot be recognized in achiral environments, such as solvent system or by normal silica gel chromatography, they can be identified in chiral settings, such as the active site of an enzyme or in a chiral stationary phase of a column. Diastereomers can also occur at a double bond, where the substituents give two superimposable isomers.