AMPS measure current
OHMS measure resistance
A series circuit is the most basic. It involves lights that are connected after another. The current divides between all the lightbulbs. If one light goes out they all go out. The lights will also be less bright than in a parallel circuit, because the current is divided.
A parallel circuit is more complicated. It involves lights that are not connected to each other, but connected to the battery seperately. If one light goes out, the others will stay lit. The lights will be brighter than a series circuit, because the current is not divided.
A combined circuit is the combination of a series and parallel. The lights will be different brightnesses depending on whether they are arranged in series or parallel.
Voltage=Current x Resistance