In the context of "12V," the "V" stands for
volts, which is the unit of electric potential or electric pressure. It represents the difference in electric potential between two points in an electric circuit.
So, when you say "12V," you're referring to a potential difference of
12 volts across a circuit or device. This voltage can cause current to flow when there is a path for the current to travel, such as in a battery, electrical appliance, or circuit.