Arrange it so that there is a current in a thin wire, and the wire will warm. The larger the current, or the greater the voltage, the greater the warming.
Warm the wire even more, and it starts to glow. That's how electrical lighting was done, but now light emitting diode bulbs (LED) and fluorescent bulbs (CFL) warm less and glow more, so are preferred. But even so, the larger the current, or the greater the voltage, the greater the warming.