Voltage is the difference in electrical potential between two points, the push that drives current through a circuit, while current is the continuous flow itself, of electricity, water or air. Checking the voltage before plugging in a foreign appliance tells you how hard the electricity will push; the current is what actually flows through the wire as a result.
The core difference
Voltage is the potential difference that drives a circuit; current is the flow that results.
- voltage — the difference in electrical potential between two points, which drives current through a circuit: A power surge can spike the voltage and damage electronics.
- current — a continuous flow of water, air or electricity in a particular direction: Electric current flows through the wire.
How to tell them apart
A simple memory hook is push versus flow: voltage is named after Alessandro Volta, inventor of the battery, and describes the electrical push between two points. Current, from Latin currere, to run, describes the actual running flow that the voltage creates, the same root behind words like currency and courier.
The mix-up shows up in everyday talk about electronics, where people say a device runs on a certain current when they really mean the voltage rating, such as 230 volts. Current is measured in amps and describes how much charge is flowing; voltage is measured in volts and describes the push behind it.
