The engine has a number of cylinders, whether it's 3, 4, 5, 6… 8…. whatever, and each one of those cylinders is designed to produce the same amount of power. If one is not able to produce the same power as the rest, then that cylinder is down and the engine might miss a bit or have a check engine light. If you think this may be the case with your automobile, this video from Eric the Car Guy will show you how to perform a power balance test on your car's engine. It's very helpful in nailing down an engine miss, if you have one.