Perspective view versus Orthographic view
3D scenes can be displayed in Perspective mode or in Orthographic mode. In Perspective mode, objects are drawn with a vanishing point. As objects get farther away from us, they look smaller, which is the way things look in real life. In Orthographic mode, however, objects stay the same size no matter how far away they are from us. In this mode, everything looks flat and close together. This can be useful for making blueprints or architectural renders, but usually, we keep the view in Perspective mode because it looks more natural:
So there it is – your first introduction to 3D! We've covered a lot of new ideas in a short time, but they will all become second nature to you once you've spent a little time working on 3D projects. Next, we'll take a look at Blender's user interface.