Conversation so far:
what are the three ways tectonic plates move
At transform boundaries, plates move past each other. At convergent boundaries, plates move toward each other. At divergent boundaries, plates move apart from each other.
can you tell me more about transform boundaries
At transform boundaries lithosphere is neither created nor destroyed.
what's lithosphere
A lithosphere is the rigid outermost shell of a terrestrial-type planet.

Question: what's under it
Self-contained rewrite: what's under the lithosphere