I should actually talk about Objects some...

An Object is anything that takes up one block-size area or greater. It could be a car, represented as, perhaps, 6 blocks. Seen from the side:

***
***

A semi-truck might be...

* * * * * *
** * * * * * *
** * * * * * *

Point being, an Object is a collection of arbitrary blocks, that the builder can give unique descriptions to, etc.

Potentially, we could do things like build a wall, and let users blow holes in walls, etc. I.e., destructable terrain of sorts.

In the semi truck example, a player could hop on top, tear through the "blocks" that represent the top, and drop down into the cargo area. Theoretically.