What does a battery do in a circuit?

It stores electrical energy charge which then provides power to the circuit. Electricity is the stream of electrons through a conductive way like a wire. This way is known as a circuit.

Batteries have three sections, an anode (- ), a cathode (+), and the electrolyte. The cathode and anode (the positive and negative sides at either end of a conventional battery) are snared to an electrical circuit.