The distributor is an electo-mechanical device which takes high-voltage electrical energy from the ignition coil and delivers it to the spark plugs in the correct order.

Most cars have one distributor, but engines with twin-plug ignition like Alfa Romeo's Twin Spark units and the 1960s Aston Martin DB4GT have two distributors.

Modern cars have solid-state ignition systems without a distributor, improving reliability and reducing maintenance.