Plate tectonics is the theory that Earth's outer shell is divided into several plates that glide over the mantle, the rocky inner layer above the core. The plates act like hard and rigid shells compared to Earth's mantle. This strong outer layer is called the lithosphere.

The main reason that Wegener's hypothesis was not accepted was because he suggested no mechanism for moving the continents. He thought the force of Earth's spin was sufficient to cause continents to move, but geologists knew that rocks are too strong for this to be true.

Huge masses of molten rock rise from deep inside Earth, cool into a solid, travel along our planet's surface and then sink back down. The process is known as plate tectonics. The term tectonics comes from a Greek word meaning 'to build.” Tectonic plates are huge moving slabs that together make up Earth's outer layer.

Plate tectonics is a scientific theory that explains how major landforms are created as a result of Earth's subterranean movements. The theory, which solidified in the 1960s, transformed the earth sciences by explaining many phenomena, including mountain building events, volcanoes, and earthquakes.

The modern theory of the motions of Earth's outer layers is called plate tectonics. It provides a framework for understanding many of Earth's features, such as mountains, earthquakes, and volcanoes, as well as the distribution of fossils and the ages of rocks.