Here's a breakdown:

* Exothermic reactions: These reactions release energy into their surroundings, usually in the form of heat, light, or sound. This means the products have lower energy than the reactants.

* Endothermic reactions: These reactions absorb energy from their surroundings, usually in the form of heat. This means the products have higher energy than the reactants.

Examples of exothermic reactions:

* Burning wood or fuel

* Explosions

* Rusting

* Neutralization of an acid with a base

Key takeaway: If a reaction feels hot or produces a flame, it's likely exothermic!