This document discusses types of isomers including enantiomers, which are nonsuperimposable mirror images. It provides examples of enantiomers including ibuprofen's R and S forms which have different biological activities. It also discusses other isomer types like diastereomers and conformational isomers. Key concepts covered include chirality, stereocenters, Fischer projections, optical activity, and methods for separating enantiomers including forming diastereomeric salts.