Faraday cage is an enclosure formed by conducting material. Like an enclosure, blocks out external static electrical fields.
The external static electrical field will cause the electrical charges within the conducting material to redistribute themselves so as to cancel the field's effects in the cage's interior. This effect is used, for example, to protect electronic equipment from lightning strikes and other electrostatic discharges.
To a large degree, Faraday cages also shield the interior from external electromagnetic radiation if the conductor is thick enough and any holes are significantly smaller than the radiation's wavelength.
