Plate tectonic theory, explains the movement of the Earths Lithosphere, which is split up to seven large plates (and a few smaller plates), which are the African, North American, South American, Eurasian, Australian, Antarctic, and the Pacific plate. Example of the smaller plates are, the Arabian, Nazca and the Philippines plates. The theory states that these rigid plates (Lithosphere) are floating on top of the (Asthenosphere), the more ductile part of the mantle. This movement causes the plates to break into pieces and to collide back together. The borders between the plates are either Convergent (moving towards each other), Divergent (moving away from each other) or it can be a transform boundary (when two plates move along each other).