How would the bulbs shine in a series circiut?

An electric light bulb, incandescant type, is designed to operate at a certain voltage. Let's take 12 volt car headlights for example. Two 12 volt lights are connected in parallel in a car to provide the headlights, the same 2 lights could be connected in series if used on a truck with a 24 volt battery, or 20 of the lights could be connected in series if connected to a 240volt home electric circuit. (In the US think of 10 connected in series on your 110 volt system.) The lights would each produce about the same light output, but the number of lights would cause more light in total.

In series there is a problem, when one light failsm they all go out. That's why lights in a house are connected in parallel.