Geometric isomers are a type of stereoisomer that occur due to the restricted rotation around a double bond or a ring structure in a molecule. These isomers have the same molecular formula and connectivity of atoms but differ in the spatial arrangement of their atoms. The two main types of geometric isomers are cis and trans isomers, where the cis isomer has similar groups on the same side of the double bond, while the trans isomer has them on opposite sides. Geometric isomerism is commonly observed in organic compounds, particularly in alkenes and cyclic structures. This phenomenon can significantly affect the physical and chemical properties of the compounds, such as boiling points, solubility, and reactivity. Understanding geometric isomers is essential in fields like organic chemistry and pharmaceuticals, where the specific arrangement of atoms can influence the behavior of a substance.