In simple terms, the endothermic reactions absorb energy from the surrounding that is in the form of heat. ... On the other hand, an exothermic reaction releases energy into the surrounding of the system. A chemical reaction that releases energy, usually in the form of heat. What's the main difference between an exothermic and endothermic reaction? An exothermic reaction releases energy and feels warm while an endothermic reaction absorbs energy and feels cool.
