Dual fuel refers to a system or engine that can operate using two different types of fuel. This technology is commonly used in vehicles and power plants, allowing them to switch between fuels like natural gas and diesel or gasoline and ethanol. The ability to use multiple fuels can enhance efficiency and reduce emissions. In addition to vehicles, dual fuel systems are also found in heating systems and generators. These systems can provide flexibility in fuel choice, often leading to cost savings and improved energy security. By utilizing two fuels, users can adapt to market changes and availability of resources.