Definition of Enantiomer
Enantiomers are those molecules which are exact mirror images of each other. Only the chiral molecules exhibit such a phenomenon. The enantiomers are not superimposable on one another that means that when one molecule is placed on the top of the other, they do not give the same molecules as they are flipped at 180 degrees. The chiral molecules which have one or more stereocenters are known to be enantiomers.
The distinct enantiomers are denoted as R or S, + or -, L and D. When the enantiomers are present in the symmetric environment, they possess almost the same physical and chemical properties, only their ability to rotate in the plane-polarized light is distinct from one another.