current
Electric current is the rate at which electric charge flows past a point in a wire — how much charge streams by each second, measured in amps. Picture water in a pipe: the current isn't the water itself, but how fast it's rushing through. A wide, fast flow means more amps; a thin trickle means very few. In a wire, the "water" is countless tiny electrons drifting along together.
Current is driven by voltage (the push) and held back by resistance (how hard the path is to flow through). More push, or an easier path, means more current. A phone charger might deliver about 1 amp; a hair dryer pulls 10 or more, which is why it heats up so fast. Too much current in too thin a wire makes it overheat — and stopping exactly that is what a fuse is built to do.
A famous quirk: by convention, current is drawn flowing from + to −, yet the actual electrons move the opposite way. Benjamin Franklin guessed the direction before electrons were known, and the world kept his "backwards" convention. The amp is named after André-Marie Ampère, an early explorer of how currents and magnetism are linked.