Ethane and methane are both gases composed of two hydrogen atoms and one carbon atom. Ethane is an alkane, while methane is a hydrocarbon. Both gases are colorless, odorless, and flammable. They are both found in the Earth's atmosphere and are important components of natural GAS. Methane is the primary component of natural GAS and is used as a fuel source for many applications. Ethane is also used as a fuel source, but it is less common than methane.