The term used to describe a chemical reaction that requires energy input is an endothermic reaction. In these reactions, energy absorbed from the surroundings is necessary to break chemical bonds, resulting in products that store more energy than the reactants. Common examples include photosynthesis, where plants capture sunlight to convert carbon dioxide and water into glucose and oxygen. The reverse reaction, in which energy is released, is termed exothermic. Understanding these concepts is essential in fields such as thermodynamics and biochemistry.