This tutorial from Ableton's Learn Live series walks through the core particle generation controls in Emit, a granular sample playback device in Live 11. Rate sets how often a new particle is created, Lifetime controls how long each one persists before being removed, and the grain count determines how many can exist simultaneously.
Randomizing Lifetime introduces variation so some particles linger longer than others, while Skip lets you thin out the stream by preventing certain particles from generating at all. Burst multiplies how many particles are produced within each Rate interval, and Spread controls whether those particles are distributed across the interval or fired together at its start.