What is the theory that states that pieces of Earth's crust are in constant, slow motion driven by movement in the mantle called?

The theory of plate tectonics state that pieces of the earth's lithosphere are in slow and constant motion that is driven by convection currents in the mantle.
As the plates move, they collide, pull apart, or grind past each other resulting in a change in the earth's surface. The changes noted include volcanoes, mountain ranges, and deep ocean trenches.
There are different types of plate boundaries. These includes:

• The divergent boundaries: These occurwhere two plates slide apart from each other.
• The convergent boundaries: These occurwhen two plates slide toward each other to form either a subduction zone or a continental collision.
• The Transform boundaries: They occur when the lithosphere plates slide and grind against each other, where they result in the destruction or creation of another plate.

Lastly, the theory of plate tectonics explains the formation, movement, and subduction of earth plates.

Plate Tectonics is the theory that states that pieces of Earth's crust are in constant, slow motion driven by movement in the mantle. The theory describes the movement of many small plates and large plates of the Earth lithosphere.

The earth crust is subdivided into several dishes, and these plates glide over the mantle, and this is due to the intense heat that arises from the middle of the Earth.

The lithosphere is the rigid shell of a planet. It is composed of seven major plates and many other minor plates. It is believed that the tectonic processes began on planet Earth around 3 billion years ago.

The tectonic theory came to be in 1960, and it states that the Earth is like a jigsaw puzzle made up of nine large plates and many smaller ones. The theory is straightforward in that there is a rigid layer which is the Earth’s surface and 30 to 60 miles deep and called the lithosphere.

This layer is on top of partially melting rocks which allows the plates to move away or towards each other while colliding or moving past each other. This movement produces, earthquakes, volcanoes and the formation of mountain ranges. They can move continents together or separate them.