In a normal, functioning circuit, electricity (current) flows in a controlled loop. It leaves the power source (like a battery or outlet), travels through wires to the "load" (a light bulb, appliance, or motor), and then returns to the source. The "load" provides , which limits the flow of electricity and allows the device to do useful work, like lighting up or spinning.
If your circuit breaker trips immediately after you reset it, you likely have a short circuit. Finding it requires a process of elimination: current short circuit