The illusions used in the film, television, theater, or entertainment industries to simulate the imagined events in a story are traditionally called special effects (a.k.a. SFX, SPFX, or simply FX).

Special effects are traditionally divided into the categories of optical effects and mechanical effects.

Mechanical effects (also called practical or physical effects), are usually accomplished during the live-action shooting. This includes the use of mechanized props, scenery, scale models, pyrotechnics and Atmospheric Effects: creating physical wind, rain, fog, snow, clouds etc. Making a car appear to drive by itself, or blowing up a building are examples of mechanical effects. Mechanical effects are often incorporated into set design and makeup. For example, a set may be built with break-away doors or walls, or prosthetic makeup can be used to make an actor look like a monster.

Text: wiki