Allows you to view particles in game which is really cool. List of particle names:
Names in italic are upcoming in Minecraft 1.13
- angry_villager - Particles that villagers emit when angry after being attacked
- barrier - The particles that show up so you know where other barriers are when you old a Barrier block in your hand
- block - The block particles: Block cracks and block dust
- bubble - Seen when entities are in water, guardians shoot lasers, and when fishing
- bubble_column_up - Seen in a bubble column when soul sand is placed underwater
- bubble_pop - Seen when bubble columns reach the surface
- cloud - Unused, looks like white smoke particles (like a cloud)
- current_down - Seen in a bubble column when magma blocks are placed underwater
- crit - Seen when you perform a critical hit on any mob (hit a mob while falling onto them), also emitted by Evocation Fangs and fully charged bows.