How to get/set the properties of terrain, and how to call a function on it?

Like, for example:

local terrain = -- terrain
terrain:Destroy()

I don’t really know what else to say, but like to get the value of the terrain, like:

terrain.Touched:Connect(function(hit)
... 

Thanks for any answers/comments!

Yes, that is great and all, but like the actual terrain. For example I have generated a lava brick with the TerrainEditor. Any ways of getting the properties with/without a script?

Thanks anyway! I am adding extra words to this post because I have a minimum of 30 characters. (LOL)