ELI5: Explain Like I'm 5

Ignition coil

An ignition coil is a type of device that is used to produce a high voltage spark in a car’s engine. It is made up of two pieces of metal, called coils, that are wrapped around a core. When electricity is applied, the metal coils build up a charge like a big battery. When the charge gets high enough, the electricity jumps from one coil to the other in a spark, like when you take off a sweater on a cold day and you get a shock! This spark is used to ignite the fuel mixture in the car's engine and make it run.