1. It is a type of stereoisomerism and it is also called cis-trans isomerism. Such type of isomerism results due to the restricted rotation of doubly bounded carbon atoms.
2. If the similar groups lie on the same side then the geometrical isomers are called as cis-is omers.
3. If the similar groups lie on the opposite side then the geometrical isomers are called as trans-isomers.