Any substance or object able to transmit electricity, or which is intended for use as a carrier for electricity. Conductivity is the measure of a conductor's efficiency. The most common conductor used in electrical energy provision is wire made of copper or a copper alloy.

Different types of conductive materials are chosen for different jobs, and the conductivity of a substance depends on the way in which that material is fabricated. For example, aluminum alloys are preferred over copper in some situations for their lower cost and lighter weight, although the use of aluminum comes at the expense of some energy loss in transmission that doesn't occur with copper. Electronic circuits may use thin copper film traced on a circuit board to conduct electricity from one component to another, but the substance that conducts electricity within a microchip is usually silicon, not copper.

As another example, copper wire used to conduct electricity to end-use customers is usually made of a single thick strand of metal, or of as few strands as practical for a given application. This type of conductor allows the highest possible throughput of electricity, but due to certain aspects of the behavior of electricity, this isn't the ideal way to carry all electrical energy. In electronic circuits such as audio equipment, the same copper or copper alloy may be used to create conductors consisting of dozens or hundreds of tiny strands. A wound or braided cable consisting of many strands won't be as efficient as a single wire and may even force the electricity to travel farther, but the electricity that arrives at the other end of the wire will be "cleaner" than the same electricity carried across a single strand because of differences in the speed at which electricity travels in different situations. This is why wound or braided wire is used to deliver electricity to devices such as loudspeakers and audio and video production devices that require exceptionally accurate transmission of electricity.

See also: