Enantiomers are compounds that are non-superimposable mirror images of each other and exhibit optical activity by rotating the plane of polarized light. This phenomenon occurs due to the chiral nature of enantiomers, which means they have asymmetrical structures that interact differently with polarized light. The rotation of polarized light is a result of the interaction between the light waves and the molecular structure of the enantiomer, leading to different optical activities for each enantiomer. For further reading, resources on chirality and optical activity in chemistry can provide deeper insights into the underlying mechanisms.