There are two basic types of electrical circuits; series and parallel. A complex circuit can consist of sub circuits of each kind.
Step 1: Series Circuit
In a series circuit, the path of electrons from the negative (-) side to the positive (+) side goes through all the electrical components of the circuit. Another way to think of this is that if you open the circuit at one point, on either side of a component, there is no complete path for the electrons to follow from - to + for any of the components. A good example of this for those of you old enough to remember is the old style Christmas lights where if one light were to burn out, the whole series of lights would go out. Series circuits are used extensively in electronics but rarely by someone who is providing power to electrical components such as supplying power to a group of lights as in the case of low voltage LED lights sold by Berkeley Point. A simple schematic of a series circuit containing three electrical components (represented as light bulbs below - icky incandescent light bulbs at that), is illustrated below: