The burning process is a continuous chemical reaction between fuel particles and oxygen. It spreads in a fire because of transfer of heat. For fire to continue the following four things are needed Fuel Oxygen Heat Chemical reactions These are often represented by the fire tetrahedron. Take away one and the fire goes out. Very many common materials can act as fuels.
Fuels come in many different forms.
Some are gases, like methane and propane, the fuels we burn in a gas cooker or a camping stove. Some are liquids like petrol and diesel, the fuels we burn in engines. And some are solids like wood and coal, the fuels we burn in fireplaces. But many other materials can be fuels. Many plastics are fuels.