Voltage

Voltage is the name for the difference in electric potential between two places in a circuit, which leads to a flow of electrons in the circuit between those places. A higher voltage means that more energy can be extracted from the flowing electrons as they go; alternatively, for a given resistance, increasing the voltage will increase the current through that resistance.

To use an analogy to water flowing in a pipe, voltage is like the pressure of the water, with higher water pressure corresponding to higher voltage.