The lithosphere is largely important because it is the area that the biosphere (the living things on earth) inhabit and live upon. If it weren't for the tectonic plates of the lithosphere there would be no change on Earth.
The system of ideas behind plate tectonics theory suggests that Earth's outer shell (lithosphere) is divided into several plates that glide over the Earth's rocky inner layer above the soft core (mantle). The plates act like a hard and rigid shell compared to Earth's mantle.
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