# Voltage |  | **Voltage**, also known as electric pressure, electric tension, or (electric) potential difference, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to move a test charge between the two points. In the International System of Units (SI), the derived unit for voltage is the volt (V). | | ---- | ---- | | | wikipedia:: [Voltage](https://en.wikipedia.org/wiki/Voltage) | |  | The **Volt** is the unit of electric potential, electric potential difference (voltage), and electromotive force in the International System of Units (SI). | | | wikipedia:: [Volt](https://en.wikipedia.org/wiki/Volt) | Voltage, or electrical pressure, is the difference in electric potential between two points.