In the introductory section, some of the fundamental concepts and theories of combustion science such as higher heating value of fuel, air to fuel ratio, flammability limits, ignition, and flame temperature are discussed. Premixed and diffusion flames are then defined and some guidelines for their analysis and understanding are outlined. Finally, the fundamentals of coal combustion are discussed. Then the technology involved in the combustion of the three most common types of fossil fuels, namely gas, oil, and coal, is discussed along with some design parameters for the combustion chambers. The most recent advances in fossil fuel combustion technology are pointed out and some of the associated problems with each fuel are explained. Finally, the impact of fossil fuels on the environment and some of the techniques available for reducing their impact are pointed out.