What is voltage?
We can simplify the concept of voltage to the electric potential that electrons have to flow from an area of higher voltage to an area of lower voltage.
We measure it in volts (
The more the voltage, the more electrons will flow in a circuit: that is what we call current.
Imagine a circuit with a LED light. You power it with a 1.5V battery, lighting up the led a little bit. If you then add a 3V battery the light will shine more, because there’s more current flowing in the circuit.
Earth has a null electric potential, 0V (zero volts), and we call it ground.
Voltage is a relative measure. It measures the difference of potential between two points. So when we say 5V for example, that’s relative to ground.
Most commercial DC (direct current) electronic devices will run at 5V or 12V.
AA batteries provide 1.5V of power. This means the
+ pole of the battery has 1.5V more voltage than the
- pole. Some devices will use multiple batteries connected with each other to provide more voltage, for example 3V with 2 batteries connected in series.
Your home is wired with a 230V (Europe) or 110V (US) AC (alternating current) and different countries might have different values.
This is why devices need a different transformer to work across different countries
We can measure voltage using a tool like a multimeter device.