An electrolyte is a substance that conducts electricity when it is melted or dissolved in water. Common electrolytes include table salt and other minerals your body needs to function properly.

When you dissolve table salt in water, it splits into tiny charged particles called ions. These ions can carry electrical signals, which is why sports drinks advertise their electrolytes: your muscles and nerves use electrical signals to work, and they need these minerals to send those signals properly.

Your body constantly uses electrolytes. When your heart beats, when you think, when you move your arm, electrical signals are zipping through your cells, carried by electrolytes like sodium and potassium. When you sweat heavily during exercise or on a hot day, you lose electrolytes along with water, which is why athletes drink special beverages to replace them. Without enough electrolytes, you might feel tired, get muscle cramps, or even feel dizzy.

Scientists also use electrolytes in batteries. The liquid inside many batteries contains electrolytes that help electricity flow from one end to the other. Whether powering your body or powering a flashlight, electrolytes make it possible for electrical energy to move where it needs to go.