Geometric isomers are a type of isomer found in compounds with restricted rotation around a bond, typically a double bond. These isomers have the same molecular formula but differ in the spatial arrangement of their atoms. The two main types of geometric isomers are cis and trans isomers. In cis isomers, similar groups are on the same side of the double bond, while in trans isomers, they are on opposite sides. Geometric isomerism is important in organic chemistry and can significantly affect the physical and chemical properties of a compound. For example, the cis and trans forms of a compound may have different boiling points, solubilities, and reactivities. Understanding geometric isomers is crucial in fields like pharmaceuticals, where the effectiveness of a drug can depend on its specific isomeric form.