Terrain.Flush, what does it do?

Documentation reads: Flushes any change done in the terrain so it takes effect.

What sort of changes does this relate to? Modifying the height/detail array? Or also the splatmap/heightmap render textures?

Seems like this isn't particularly necessary for any kind of change. Does anyone know what the benefit is of calling this function?

 

Hey, I'm curious if you've found any situation where it's necessary to use terrain.Flush()