### Voltage as Electrical Pressure

**Voltage (V)**, or _electric potential difference_, is the work required to move a unit charge between two points.

- **Potential difference:** ΔV = V₂ – V₁
- **Pressure analogy:** Pushes electrons through conductors like water pressure pushes fluid in pipes
- **Unit:** Volt (V) = joule per coulomb (J/C)

Grasping voltage is essential for circuit design, wire sizing, and component selection.