Tectonic plates are large, irregularly shaped slabs of solid rock that make up Earth's outer shell, known as the lithosphere. This lithosphere includes the crust and the uppermost mantle and is typically about 100 km (60 miles) thick. The plates consist of two types of crust: the denser oceanic crust and the thicker, less dense continental crust. These plates float on the softer, partially molten layer beneath called the asthenosphere, which allows them to move

. There are seven or eight major tectonic plates, along with many smaller ones, covering Earth's surface. These plates move relative to each other at rates of a few centimeters per year, interacting along their boundaries in three main ways: convergent (colliding), divergent (pulling apart), and transform (sliding past each other). These interactions cause geological phenomena such as earthquakes, volcanic activity, mountain-building, and the formation of ocean trenches

. Tectonic plates play a crucial role in shaping Earth's surface and geography over millions of years by causing continents to drift, mountains to rise, and oceans to form. Their movement is driven by forces such as mantle convection and the sinking of dense oceanic crust into the mantle at subduction zones