The movement of tectonic plates is termed plate tectonics. This geological theory explains how the Earth's outer shell, or lithosphere, is divided into several large and small plates that float atop the semi-fluid asthenosphere below. These tectonic plates continuously shift due to convection currents caused by the heat from the Earth's interior. This movement can result in various geological phenomena, including earthquakes, volcanic activity, and the formation of mountains. Plate tectonics influences the distribution of ecosystems, natural resources, and human settlement patterns, playing a fundamental role in shaping the planet's landscape over millions of years.