Particle effects are both cool and a huge time saver. You can create atmospheric effects, such as rain, grass or fire to more complex systems, such as swarms of animated insects-- all in a fraction of the time it would usually take.
Particle effects act in the same way as all other effects in Harmony, except they always work within their own specifically structured system. You can attach a Blur effect node under a Drawing node and the image contained in the Drawing node will become blurry. Particle effect set-ups are more complex than simply adding a node and playing with its parameters. To keep things simple, just think of each Particle effect as its own group.