Particles

Particles are useful when you need to create and animate a lot of objects that behave similarly. Imagine, for example, snow, rain, or leaves falling; instead of animating each snowflake or raindrop individually, you create an emitter geometry and, on the Particles tab in the Properties panel, you add a Particle System to it.

From there, you can set the amount of emitted particles, their behavior, their physics, and so forth. You can also select other objects and set them as obstacles, so particles collide with them. You can even create forces such as wind, vortex, or turbulence to make the particles behave in certain ways. You can also use particles to simulate fluid substances.