ACS using attachment in workspace.Terrain for its VFX

I’m trying to understand how and why ACS uses an attachment in a terrain for VFX on the client.

		local Attachment = Instance.new("Attachment", workspace.Terrain)
		Attachment.CFrame = CFrame.new(Position, Position + Normal)

The module is big so this is just what I saw. I saw the attachment being used continuously as a parent for sounds and particles.