The lithosphere is the outermost layer of the Earth, consisting of the crust and the upper part of the mantle. It is made up of solid rock and is where we find landforms like mountains, valleys, and plains. The lithosphere plays a crucial role in supporting life, as it provides the ground we walk on and the minerals we need. This layer is also involved in tectonic activity, where large pieces called tectonic plates move and interact. These movements can cause earthquakes and volcanic eruptions, shaping the Earth's surface over time. Understanding the lithosphere helps scientists learn more about our planet's processes and history.