Video narration
How can a tiny switch control a flow much bigger than itself? Picture a faucet: a small turn controls a larger stream. A transistor does something similar, but its flow is electric current, not water-and nothing twists. Take one common kind, a MOSFET: a transistor whose gate is its control point. A voltage at the gate controls whether a path forms for current through the device. But the gate doesn't carry the main current. Its electric field creates or removes the path. When that path forms, current flows; without it, the switch is off. Now repeat that tiny on-off action at enormous scale. Chips contain vast numbers of transistors, switching together to handle information. Those switches are packed into the chips behind phones, computers, and the many electronic systems you rely on each day. A small voltage opens or closes the current path-with no moving parts.