What is voltage mail

I think you meant to ask "What is voltage mail?"

Voltage mail is not a real thing, and I'm assuming it's a typo or a made-up term. However, I can try to help you understand what voltage is and how it relates to electricity.

Voltage is the measure of the potential difference between two points in an electric circuit. It's measured in volts (V) and is represented by the symbol "V". Voltage is the "pressure" that drives electric current through a circuit. The higher the voltage, the greater the force pushing the electrons through the circuit.

In other words, voltage is the "pressure" that makes electrons flow through a wire. Think of it like water flowing through a hose. The water pressure (voltage) determines how fast the water flows (current).

If you meant to ask about something else, please feel free to clarify or provide more context, and I'll do my best to help!