Serial and Parallel Circuits (Physics)

There are two basic ways to connect more than two circuit components: series and parallel.
An example of a series circuit:


In series circuits, all current goes through every load; there are no forks or branches in the circuit. So, the current, I₁, through resistor, R₁, and the current, I₂, through resistor R₂ are the same and equal to the current, I, of the circuit.


The other type of circuit, a parallel configuration:

Not all the current goes through every load. There is at least one fork or branch in the circuit. In the diagram above, the current that leaves the source is split. Some current, I1, goes through R1 and the rest, I2 goes through R2 . The sum of the currents I1 and I2 equals the total current.