You can learn a lot from wikipedia.
Gasoline (gas), petroleum spirit (petrol) or petrogasoline is a liquid mixture primarily used as fuel in internal combustion engines. It is petroleum-derived, and consists mostly of aliphatic hydrocarbons, enhanced with iso-octane or the aromatic hydrocarbons toluene and benzene to increase its octane rating.
Gasoline (gas), petroleum spirit (petrol) or petrogasoline is a liquid mixture primarily used as fuel in internal combustion engines. It is petroleum-derived, and consists mostly of aliphatic hydrocarbons, enhanced with iso-octane or the aromatic hydrocarbons toluene and benzene to increase its octane rating.