A volt is a unit that measures electrical pressure, or how much force pushes electricity through a wire. Just as water pressure helps determine how strongly water flows through a hose, voltage helps determine how strongly electricity flows through a circuit.

When you see “9V” on a battery or “120V” on an outlet, that number tells you the electrical pressure available. A 9-volt battery provides enough push for a small radio or smoke detector, while a 120-volt wall outlet (standard in American homes) provides much stronger pressure for lamps, computers, and refrigerators. High-voltage power lines carry electricity at thousands of volts to move it across long distances.

Understanding volts helps explain why you can safely touch a 9-volt battery under normal conditions but should never touch a wall outlet: higher voltage means stronger electrical pressure, which can be dangerous. Electricians, engineers, and anyone working with electricity constantly think about voltage to help ensure devices work properly and safely.