Is combustion an exothermic reaction or an endothermic reaction?
When a fuel reacts with Oxygen in a combustion reaction, a large amount of heat is generally released. (Something like a candle or a match for example, will also release heat in smaller amounts). The ‘Release’ of Heat Energy is an ‘Exothermic’ reaction. When standing in front of a Fire, you feel the Radiated heat from the flames caused by the reaction. Convected heat causes the flow of Oxygen into the reaction. The hot combustion gases rise due to decreased density and cool air (oxygen) flows into the fire to replace it. My own knowledge without Wikipedia, having worked for years with boilers and furnaces and their control.