What device ignites gas in car engines?

A spark plug is a device that ignites the fuel mixture in the combustion chamber of a gasoline-powered internal combustion engine. It consists of a ceramic barrel, an electrode (the positive terminal), and an insulator that separates them. The electrode is connected to a high-tension wire from the ignition coil, which supplies a series of high-voltage electrical pulses. These pulses create an electric arc (or spark) between the electrode and the engine's metal ground, causing the fuel mixture to ignite and create pressure that drives the piston down.