Here's why:

* Lithosphere: This is the rigid outermost layer of Earth, composed of the crust and the uppermost part of the mantle. It's broken into tectonic plates that move and interact, causing earthquakes and volcanic activity.

* Crust: The thin, outermost layer of Earth, composed of solid rock. It's divided into oceanic crust (thinner and denser) and continental crust (thicker and less dense).

So, the crust is a crucial component of the lithosphere, but it's not the entire lithosphere.