1. A vanishing point is when you take all of the lines that have to do with width or depth and pull them back to create a more dimensional drawing.
2. It is the perspective that you see it with a one you see it a lot longer. With a two you see it wider. Then with a 3 point perspective you see it wider and deeper.
3. When you have a perspective drawing you see the depth of everything and with an Isometric drawing it is not as deep or wide.