What are tectonic plates?How were continents formed?

A) Plate tectonics is the theory that Earth's outer shell is divided into large slabs of solid rock, called “plates,” that glide over Earth's mantle, the rocky inner layer above Earth's core. ... Below the lithosphere is the asthenosphere — a viscous layer kept malleable by heat deep within the Earth.

B) About 250-million years ago, long, long after the Earth had formed, all the continents of the time had joined together to form a super-continent called Pangaea. This super-continent broke up about 200-million years ago to form two giant continents, Gondwana and Laurasia.

Just do the math, then think