The theory also says that plate tectonic is the movement and because of this movement Earth changes. Plate boundary is when the plates meet. There are three different kind of plate boundary. Convergent boundary is when plates come together and forms volcanoes and mountains. There different type of volcanoes and mountains, Shield volcano, composite volcano,and cinder cone, those volcanoes also have similarities and differences. Folded mountains and fault block mountains form s differently too. Divergent plate boundary is when plates move apart from each other and forms rift valleys, mid ridge ocean. The transform plate boundary is when plates slide past each other and forms earthquakes and tsunamis. 
Continental drift is a theory thought by Alferd Wagener, it says that that continents are like puzzles and it can come together. A lot of people thought that he is crazy, but overtime peoples started to see the effects. Then they believed in that theory. Convection currents makes the plates move. Because the mantle makes the pressure to go up of it hotness, when it goes up there will be no effect. Because the crust is not hot.
In conclusion I believe in theory of plate tectonics. Because all the evidences shows that earth can move and the continents can come together. There are a lot of effects of the movement. Like earthquakes, tsunamis, different type of mountains and ect...
