Proportion

formal—> comparative relation between things ormagnitudes as to size, quantity, number, etc.;ratio.

source—> http://www.dictionary.com/browse/proportion

informal—> a part that is shared with something.

Rule of thirds

formal—> The basic principle behind the rule of thirds is to imagine breaking an image down into thirds, both horizontally and vertically, so that you have 9 parts

source—> https://digital-photography-school.com/rule-of-thirds/

informal—> a subject that has guidelines with intersections.

Golden rule

formal—> It is a compositional rule of thumb that is commonly used in the visual arts today including painting, photography and design. Perhaps the most well know principle of photographic composition is the ‘Rule of Thirds’.

source—> http://www.drawinghowtodraw.com/drawing-lessons/art-design-principles/golden-ration-divine-proportions.html

informal—> geometric compositions which is repeated continuously in different sizes,