The document discusses the Golden Ratio and Rule of Thirds. The Golden Ratio is a ratio between segments of a line where the ratio of the larger segment to the smaller is the same as the ratio of the larger segment to the whole. A golden rectangle is one with side lengths in this ratio, and removing a square from it leaves another golden rectangle. The Rule of Thirds involves dividing an image into thirds and placing key elements along these lines or their intersections for improved composition.