The term particle system refers to a computer graphics technique to simulate certain fuzzy phenomena, which are otherwise very hard to reproduce with conventional rendering techniques. Examples of such phenomena which are commonly done with particle systems include fire, explosions, smoke, flowing water, sparks, falling leaves, clouds, fog, snow, dust, meteor tails, or abstract visual effects like glowing trails, magic spells, etc.

Particle System
A particle system builds an image component using a collection of points or primitives rather than by stringing polygons together. These points can be programmed with unique attributes that dictate how they behave as a group and particle systems have been used to create everything from smoke and fire to flocking birds and fountains.