What do you understand by the term “plate
tectonics? what is the reason for its occurrence?

plate tectonics, theory dealing with the dynamics of earth's outer shell the lithosphere that revolutionized earth sciences by providing a uniform context for understanding mountain-building processes, volcanoes, and earthquakes as well as the evolution of earth's surface and reconstructing its past continents

hope this x

answertemperature;

heat from the core of the earth causes convection currents to occur in the mantle. these currents slowly move the crust around.