VAC would be the abbreviation of Volt Altern Current which would be translated Volts of alternating current. The difference between VDC is that its sinusoidal oscillation achieving a more efficient energy transmission.

The alternating current is the energy that we receive in our homes, it is generated in the power plants by means of alternators.

The intensity of this type of current varies with time, and changes direction 50 times throughsecond (50hz). The generated voltage changes in the form of sine wave so it is not constant.

In the image:

1. Current by pulsations.
2. Direct current (DC).
3. Alternating current (AC).
4. Variable current.

DMX512, often shortened to DMX (Digital Multiplex), is an electronic protocol used in lighting control of the light show, enabling communication between the teams control their own lights and light sources.

DMX512, also known as DMX to dry is the most widely used protocol in lighting today. The lighting allows lighting control in shows. The DMX can control multiple light emitting visual elements, such as cannons, strobe lights and others, from a single issuer.