Examples of common combustion processes are burning candles, forest fires, log fires, the burning of natural gas in home furnaces, and the burning of gasoline in internal combustion engines.
Fuels can be solid, liquid, or gas.
Examples of solid fuels include filter paper, wood, and coal. Liquid fuels include gasoline and kerosene. Propane and hydrogen are examples of gaseous fuels. Air, which contains oxygen, is a particularly common oxidizer. An electrical spark is an example of an ignition stimulus.