SERIES: The advantage of a parallel circuit is that if one of the output devices burns out, then only that device stops working. Thedisadvantage is that if you have multiple power sources, the power stays at the same voltage as that of the single power source. But in parallel circuits increasing the number of output devices does not increase the resistance the way it does in series circuits.
n advantage of a series circuit is that you can add more power devices, such as more batteries, and increase the force of the output. This will give you more power. One disadvantage is is that as you add output devices, such as light bulbs, you increase the resistance and the bulbs do not shine as brightly. Another important disadvantage is that if one output device stops working, all the other output devices will stop working, too. This is because all of the power and output devices are connected in a straight line. When one fails, you have a broken circuit and nothing will work.