An electric circuit is a closed circuit which allows electrons to flow continuously. This flow, or current, of electrons is called voltage. Voltage is a measure of potential energy between two points.
Electric circuits are often built on a circuit board which supports the connecting components.All About Circuits: How voltage, current, and resistance relate
Ohm's Law
Ohm's Law is the relationship between current, voltage and resistance. It states that the amount of electrical current through a circuit is directly proportional to the voltage. physics.uoguelph.ca: Ohm's Law