The primary mechanism behind tectonic plate movements is mantle convection. The Earth's mantle consists of semi-solid rock that behaves like a viscous fluid over geological timescales. Heat from the Earth's core generates convection currents within the mantle, causing tectonic plates, which are rigid segments of the Earth's lithosphere, to move. This movement may lead to the formation of mountains, earthquakes, and volcanic activity at plate boundaries. Understanding this process is essential for comprehending Earth's geological features and events.