A fog machine, fog generator, or smoke machine is a device that emits a dense vapor that appears similar to fog or smoke. Fog machines are most commonly used in nightclub or professional entertainment applications, but smaller, more affordable fog machines are becoming common for DJ's or personal use. Fog machines can also be found in use in a variety of industrial, training, and some military applications.
Typically, fog is created by vaporizing proprietary water and glycol-based or glycerin-based fluids or through the atomization of mineral oil. This fluid (often referred to colloquially as fog juice) vaporizes or atomizes inside the fog machine. Upon exiting the fog machine and mixing with cooler outside air the vapor condenses, resulting in a thick visible fog. Fog machines are a must to add that 3D element of lighting effects you see in a nightclubs or and venue that you really want to see the lights textures and awesome colors, or if using lasers, you will fog to see the laser beams in the air for aerial laser beam effects