A Faraday cage is a cage or enclosure that protects sensitive electrical equipment from electrostatic interference. It is made of grounded meshed wire or parallel wires.
The cage channels electricity through the mesh and provides constant voltage on all sides of the enclosure. The electrical current does not flow into the cage because the difference in voltage is the measure of electrical potential. The cage's conducting material distributes the electrical charges so that they cancel the effect on the inside of the cage.
The Faraday cage is used to protect electronic instruments from electrostatic discharges and lightning strikes. The cage was invented in 1836 by English scientist Michael Faraday. Some examples of Faraday cages are microwave ovens, elevators, coaxial cables, USB cables, booster bags and airplane passenger compartments.