Spark gap

A spark gap consists of an arragement of two conducting elements that control the movement of electrons or ions. It is composed of a set of conductorss in which a disruptive and violent discharge of electromagnetic energy (known as a current) passes from one node to the other node. The dielectric medium that reduces the transmission of electricity between the two nodes reestablishes itself after the transition of the discharged current.

A spark plug uses a spark gap to initiate combustion.