Here's a breakdown:
* Lithosphere: This is the rigid outer layer of the Earth, composed of the crust and the uppermost part of the mantle. It's broken into tectonic plates.
* Asthenosphere: This is a semi-molten, plastic-like layer of the upper mantle. It's hot and under immense pressure, allowing it to deform and flow very slowly. The tectonic plates "float" on this layer.
* Mesosphere: This is the lower part of the mantle, a solid layer that extends to the Earth's core.
It's important to understand that the plates don't slide directly on the asthenosphere like a piece of paper on a table. Instead, they move due to convection currents within the asthenosphere, where hotter, less dense material rises and cooler, denser material sinks. This creates a slow, continuous movement of the plates.
