A conductor (in electricity) is a material that allows electric charge to flow through it easily due to the presence of many mobile charge carriers such as free electrons or ions.

Key properties of a conductor

  • High electrical conductivity
    Conductors have a large number of free electrons (in metals) or other mobile charges that can move under an electric field, so current flows easily.
  • Low electrical resistance
    Because charges move easily, conductors oppose current only weakly; resistance is low for a given length and cross‑section compared with insulators or semiconductors.
  • Positive temperature coefficient (for most metals)
    For metallic conductors, resistance typically increases as temperature increases, because atoms vibrate more and scatter electrons more strongly.
  • Ohmic behavior (for ideal/simple conductors)
    Many common conductors approximately obey Ohm’s law, meaning current is proportional to applied voltage at constant temperature, although real materials have limits where this linearity breaks down.
  • Good thermal conductivity
    Many electrical conductors (like copper and aluminum) are also good heat conductors, since the same free electrons that carry charge help carry thermal energy.
  • Reflective and metallic luster (for metal conductors)
    Metals often look shiny because free electrons interact strongly with electromagnetic waves, causing reflection over a wide range of frequencies.
  • Screening and shielding ability
    In a conductor at electrostatic equilibrium, free charges rearrange so that the electric field inside the bulk is effectively zero, which is why conductors are used for electromagnetic shielding (like cable braids and Faraday cages).
  • Wide range of mechanical forms
    Practical conductors can be drawn into wires, made into foils, or formed into busbars; engineers choose size and shape based on current capacity, allowable heating, and mechanical strength.

Common examples and context

  • Metals such as copper, aluminum, silver, and gold are widely used electrical conductors in wiring, electronics, and power systems.
  • Conductive solutions (electrolytes) and plasmas also act as conductors, but their mobile charges are ions rather than free electrons in a metal lattice.

In everyday terms: a conductor is any material that lets electricity “flow” through it easily, has low resistance, and is therefore used wherever we need to carry current efficiently, like wires, connectors, and busbars.