Copper is used in many wires because it has a lower resistance than many other metals. The wires in your walls, inside your lamps, and elsewhere are mostly copper. American homes use 110 volts of electric power for regular appliances. Larger appliances, like a clothes dryer or stove, use 220 volts. Some countries use 220 volts for all of their appliances and electric devices.
Batteries contain stored chemical energy.
When the chemicals react with each other, they produce an electrical charge. This charge changes into electrical energy when the battery is connected in a circuit. Along the circuit you can have a light bulb and on-off switch. The light bulb changes the electrical energy into light and heat energy. You can have a heating element.