Which part of the Particle System determines how long particles are visible?

The lifetime of particles in a particle system refers to the duration for which each particle remains visible after it is emitted. This setting dictates how long a particle exists before disappearing, effectively controlling the visual impact of the particle effects in a scene.

When the lifetime is set, it defines a specific duration that can be influenced by randomness to create a more dynamic and interesting effect. A longer lifetime means particles remain visible for a more extended period, potentially enhancing specific visual effects, while a shorter lifetime can create a more transient appearance, making effects like smoke, sparks, or confetti look more realistic and ephemeral.

The other options relate to aspects of the particle system that impact different characteristics of the particles but do not specifically govern their visible duration. Emission Rate controls how many particles are generated over a set time, Size influences how large each particle appears, and Velocity affects how quickly the particles move through space. However, none of these directly determine how long each particle will be visible once created.