Enantiomers are a type of stereoisomer where the molecules are non-superimposable mirror images of each other. In chemistry, this property is referred to as chirality. Each enantiomer of a chiral molecule is designated as either R- or S- (from the Latin rectus and sinister, meaning right and left, respectively) based on their spatial arrangement. The presence of an asymmetric carbon atom, often referred to as a chiral center, is what gives rise to enantiomerism in a compound.
