A series circuit consists of a single pathway through which electricity can flow. All of the parts of a series circuit power source, wires, and devices are connected along the same pathway, the devices are connected one after another, with no branches. Current moves through one device, then the next, and so on.The amount of current is the same at every point in a series circuit. However, the amount of current for each device in a series circuit decreases as more devices are added to the circuit.
Parallel wiring allows the electric current to move through different pathways. Each branch can be switched on or off independently, allowing some or all of the devices to be used. In general, if the resistance along a given parallel branch is increased, a smaller amount of current will flow through that branch. The more branches that are available in parallel wiring, however, the lower the total resistance in the circuit becomes, and thus the higher the total current.