Here's why:

* Lithosphere: The rigid outer layer of the Earth, composed of the crust and the uppermost part of the mantle.

* Tectonic Plates: The lithosphere is broken into large, irregularly shaped pieces called tectonic plates. These plates are constantly moving, interacting with each other, and causing various geological phenomena.

There are indeed approximately 30 major tectonic plates, with some being smaller microplates.