What is a Particle System?
Particles are small, simple images or meshes that are displayed and moved in great numbers by a particle system. Each particle represents a small portion of a fluid or amorphous entity and the effect of all the particles together creates the impression of the complete entity. Using a smoke cloud as an example, each particle would have a small smoke texture resembling a tiny cloud in its own right. When many of these mini-clouds are arranged together in an area of the scene, the overall effect is of a larger, volume-filling cloud.