The continental drift is the displacement of the continental mass relative to each other. But he can´t explain it properly until the 60´s when was developing the plate tectonics.
The theory of wegener was based in the way that fit the continents on it´s side of the atlantic ocean, Africa and South America.
also took in to account the similarity of fossil fauna of the septentrials continents. In summary Wegener said that the set of actuals continents were jointed in the past, form an suppercontinent called Pangea, that means ¨All the Earth.¨