Electrical basics

Let's look at a few of the terms and concepts you'll need to understand when working with circuits.

Parallel

Parallel elements are connected so that they share a connection at each terminal. You can think of them being connected "side-by-side."

Series

Series elements are connected so that they form a chain of connected elements. You can think of them as being connected "end-to-end."

Voltage

Voltage is measured in Volts (V).

Voltage is sometimes referred to as "electromotive force." It is also sometimes referred to as "potential." These notions are ways of expressing the idea that voltage is analogous to the pressure of water in a closed pipe.

Voltage is always measured "across" a circuit element, or between two points. Voltage at one point in a circuit is measured relative to another point. For example the voltage across a resistor is measured by placing probes at either end of the resistor while the resistor remains in place in the circuit.

All elements in a parallel circuit have the same voltage across them.

Current

Current is measured in Amperes, usually shortened to Amps (A).

Current flows through a circuit element. It is measured by placing your meter probes in series with the circuit element, interrupting the original circuit path.

All elements in a series circuit have the same current flowing through them.