Final answer:
Continental drift is exemplified by the concept of Pangaea, while seafloor spreading is represented by oceanic ridges, oceanic plates under continental crust, and magma separating plates. These processes are central to the theory of plate tectonics.
Step-by-step explanation:
The concept of Pangaea relates to Alfred Wegener's hypothesis of continental drift, which posits that continents have moved over geological time to their current locations, and that they were once joined together in a supercontinent. The oceanic ridges, along with magma pushing two plates apart and oceanic plates sliding under continental crust are examples of seafloor spreading—a process integral to the theory of plate tectonics, which was developed further by scientists like Harry Hess and involves the renewal and recycling of oceanic crust at oceanic ridges.
In answering the question, we determine that oceanic ridges, oceanic plates sliding under continental crust, and magma pushing two plates apart represent seafloor spreading. The concept of Pangaea is an example of continental drift. These concepts have shaped our understanding of Earth's geological history and the dynamic nature of its surface.