Flick a switch and the light comes on. Charge your tablet, ring a doorbell, keep the fridge cold — almost everything in your home runs on electricity. But what is it, and how do we make it do what we want?

Electricity is a flow of tiny invisible bits of charge moving through metal wires — a bit like water flowing through a pipe. To make it flow you need to give it a complete loop to travel round, called a circuit. Break the loop anywhere and the flow stops.

Here is the simplest circuit there is: a battery to push the charge along, a bulb to light up, and a switch to make or break the loop. Flick the switch from Open to Closed and watch the bulb come on — because now the charge has a complete loop to flow around.

Your electricity adventures

Begin by building a simple circuit that lights a bulb. Then learn how a switch turns it on and off, why electricity flows through some materials but not others, and how to make a bulb glow brighter or dimmer.