Enantiomers are a type of stereoisomer that are mirror images of each other but cannot be superimposed. They have the same molecular formula and connectivity of atoms, but their three-dimensional arrangements differ. This property is crucial in fields like pharmaceuticals, where one enantiomer may have therapeutic effects while the other could be inactive or harmful. These compounds often exhibit different optical activities, meaning they rotate plane-polarized light in opposite directions. One enantiomer is referred to as "right-handed" or dextrorotatory, while the other is "left-handed" or levorotatory. Understanding enantiomers is essential in chemistry and biochemistry for developing effective drugs and understanding biological processes.