Illusion of Space

Overlapping: a device that adds depth to a picture by layering shapes into one another.

Quack! The front duck is overlapping the back one.

Aerial Perspective: A phenomenon that makes shapes far away to look without contour, less colorful and fuzzy.

The mountains seem washed away as they recede .

Linear perspective: It is a phenomenon that makes parallel lines intersect as they recede.

This railroad tracks intersect at some point far away, even though the metal bars are parallel  to each  other.