1. An unbroken path of material that carries electricity via an electrical conductor; such as, copper wire.

Electric lights, televisions, radios, and other electrical instruments function because of an electric circuit that starts at a power plant which generates electricity and ends up where people have outlets that allow the electric current to perform.

2. The path of the electron flow from a generating source through various components and back to the generating source.
3. A closed path that conveys an electric current through a conducting material which can be made of ionized gases or ionized liquids, but metals are most commonly used.

The most simple electric circuit consists of a source of electricity; such as, a battery and a conducting material as a wire

Current flows from the positive terminal of the battery through the wire to the negative terminal.

A resistor; such as, a light bulb can be added to the circuit, as can a switch that can be used to open the wire. Current flowing through the wire will light the bulb unless the switch is used to cut the circuit off.

The mathematical analysis of conditions and relationships in an electric circuit.