Circuits are not limited to only series or only parallel configurations. Most circuits contain a mix of series and parallel segments. A good example is a household circuit breaker. Electrical outlets in each section of the house are wired in parallel with the circuit breaker for that section wired in series making it easy to cut off electricity to the parallel parts of the circuit when needed.

Fuses are thin wires that melt when the current in a circuit exceeds a preset amount. They help prevent short circuits from damaging circuit components when an unusually large current is applied to the circuit, either through component failure or spikes in applied voltage.

Splicing is permanently joining two wires together. Splicing can be done with screw-on connectors or wire crimps but the preferred method for splicing is soldering. Soldering takes the most effort but results in a connection that is electrically and mechanically identical to the original wire.

Voltage (V) is the electrical potential difference between two points. Electrons will flow as current from areas of high potential (concentration of electrons) to areas of low potential. Voltage and current are directly proportional in that the higher the voltage applied to a conductor the higher the current that will result.

A photovoltaic cell (also known as a solar cell) converts energy from the sun into electrical energy.