Perspective is showing distance on a flat surface, which adds a 3-D look to a drawing. For instance, in da Vinci's The Last Supper , the windows in the background of the painting reveal the landscape and nature in the distance. The scene through the windows illustrates a vanishing point and gives the viewer a better perspective of the setting. As its name indicates, the vanishing point is where things seem to disappear in the distance. There can be many vanishing points within a drawing.
Objects appear to be closer together at the vanishing point.
Objects appear smaller at the vanishing point. Details and colors fade at the vanishing point. The foreground of the artwork should be drawn using the exact opposite of these principles.