Olefins are unsaturated hydrocarbons that contain at least one carbon-carbon double bond in their molecules. They are commonly used in the production of polymers, plastics, and other chemicals. There are several synonyms for olefins, including alkenes, aliphatic hydrocarbons, and ethylenes. Alkenes refer to hydrocarbons that contain at least one carbon-carbon double bond, while aliphatic hydrocarbons refer to organic compounds that are made up of carbon and hydrogen atoms arranged in a straight or branched chain. Ethylenes, on the other hand, specifically refer to hydrocarbons with a double bond between two carbon atoms. These synonyms are frequently used in the scientific literature, and understanding them is important for professionals working in the chemical industry.