G What is the main difference between Wegener's Continental Drift and the Theory of Plate Tectonics?

The main difference between them is that; Wegener's Continental Drift postulates that earth was made up of a single continent, while the theory of Plate Tectonics states that earth's surface is broken into numbers of shifting plates or slabs.

Explanation:

Wegener's Continental Drift was a theory set forth by Alfred Wegener in 1912. He explained how continents shift positions on earth's surface. This movement happened over geologic time relative to each other, thus appearing to have "drifted" across the ocean bed.

While on the other hand, the Theory of Plate Tectonics is the theory that the outer shell of earth is divided into several plates that glide over the mantle (the rocky inner layer above the core). The plates act like a hard and rigid shell compared to Earth's mantle.