Meet the Components

Beyond wires and bulbs, real circuits use a handful of key components that each do something specific.

• Resistors limit current flow and protect sensitive parts — they're the bouncers of the circuit
• Capacitors store charge temporarily, smoothing out voltage spikes like a shock absorber
• Diodes allow current to flow in only one direction — one-way streets for electrons
• Transistors act as tiny switches or amplifiers — billions of these live in your phone's processor.