Constitutional isomers
Least similar. Only share same molecular formula
Structural isomers
Least similar. Only share same molecular formula
Stereoisomers
Same chemical formal and same atomic connectivity.
Conformational isomer
Does not require bond breaking to convert. Type of stereoisomers. (Newman projections)
Configurational
Requires bond breaking to convert. Type of stereoisomer.
Geometric isomer
Isomerism is at a double bond. Type of configurational isomer
Optical isomer
Isomerism is not at a double bond. Type of configurational isomer.
Enantiomers
Optical isomers that are non-superimposable
Diasteriomers
Optical isomers that are super impossible mirror images