Here's how it works:

* Convection Currents: The Earth's mantle, a layer of hot, semi-solid rock, is constantly in motion. Heat from the Earth's core creates convection currents, similar to boiling water in a pot. Hotter, less dense material rises, while cooler, denser material sinks.

* Seafloor Spreading: As the hot mantle material rises, it exerts pressure on the Earth's crust, causing it to crack and break apart. Magma from the mantle erupts at these cracks, creating new oceanic crust along mid-ocean ridges. This process is called seafloor spreading.

* Continental Drift: The newly formed oceanic crust pushes away from the mid-ocean ridges, carrying the continents with it. This process is called continental drift.

Key Points:

* Plate Tectonics: The theory of plate tectonics explains how the Earth's outer layer (the lithosphere) is divided into plates that move and interact with each other. Seafloor spreading and continental drift are two key aspects of this theory.

* Driving Force: Convection currents in the mantle are the driving force behind plate tectonics.

Let me know if you have any other questions.