Learn the fundamentals of electricity, then build your own working circuits with our interactive circuit builder below!
Everything around you is made of tiny particles called atoms. Each atom has even tinier particles called electrons that orbit around it. Electricity is what happens when these electrons move from one atom to another in a flow — kind of like water flowing through a pipe.
When electrons flow through a material like a copper wire, we call that flow electric current. To get electrons moving, we need something to push them — that push is called voltage, and it comes from a power source like a battery.
Think of it like a water park: A battery is like the pump that pushes water up to the top of a water slide. The wires are like the slide itself — the path the water flows through. A light bulb is like a waterwheel along the path — it uses the water's energy to do something useful. And voltage is how high the pump pushes the water — more height means more energy!
Fun fact: Electricity travels through wires at nearly the speed of light — about 670 million miles per hour! But individual electrons actually move quite slowly, only about 0.01 cm per second. It's the electrical signal that travels fast, like a wave passing through the wire.
Before we start building circuits, let's learn the important words scientists and engineers use when talking about electricity.
Every circuit is built from just a few basic parts. Here's what each component does and how it works in the circuit builder below.
There are two fundamental ways to arrange components in a circuit. Each has different properties — understanding the difference is a core skill in electronics.
Components are connected in a single loop, one after another. Current flows through every component in order. If one bulb burns out, the entire circuit breaks and everything turns off.
Components are connected on separate branches so current splits and flows through each path independently. If one bulb burns out, the others stay lit because their branch still works.
Did you know? Almost all household wiring uses parallel circuits. That way, each outlet and light works independently. Series circuits are used in some special applications, like the dimmer circuits in some LED light strips.
Our circuit builder is perfectly safe to experiment with, but real-world electricity can be very dangerous. Here are the most important safety rules.
Never touch exposed wires, outlets, or electrical equipment with wet hands. Water is a conductor and lowers your body's resistance, making electrical shocks much more dangerous. Never stick anything into an electrical outlet, and always have an adult supervise any real electricity experiments. If you see a downed power line, stay far away and tell an adult immediately.
Use the tools below to place components on the grid, wire them together, and hit Simulate to watch electrons flow through your creation.
Select a component from the toolbox and click on the grid to place it. Use the Wire tool to connect component terminals (the small circles). A complete circuit needs a battery, at least one load (bulb or resistor), and wires connecting them in a loop. Click Simulate to see electrons flow!