Blender has several physics simulations that support collisions, such as fluid and rigid body. Use this tag for questions about collisions in physics simulations.
Blender physics simulations allow you to simulate the interaction of bodies through collisions. Fluid simulations have specific objects called Effectors that provide the collision simulation in the fluid domain, while other physics simulations have collision settings.
This tag can be used for questions about any of the forms of collision in physics simulations.