An exothermic reaction is a chemical process that releases energy, usually in the form of heat or light. During this reaction, the total energy of the products is lower than that of the reactants, resulting in the release of energy to the surroundings. Common examples include the combustion of fuels, such as in wood burning or gasoline in engines. These reactions are important in various applications, including heating systems and energy production. In everyday life, exothermic reactions can be observed in activities like lighting a match or using a hand warmer, where heat is generated as a result of the chemical changes taking place.