Proportion “a part, share, or number considered in comparative relation to a whole” (google)
Rule of Thirds “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”
A guideline cut into thirds mostly used for photography and film.
Golden Rule “There’s a common mathematical ratio found in nature that can be used to create pleasing, natural looking compositions in your design work.” (http://www.creativebloq.com/design/designers-guide-golden-ratio-12121546)
A Ratio used to calculate a design.