Stained glass windows in Gothic cathedrals served as "Bibles of the Poor" by using symbolism and imagery to teach scripture to illiterate parishioners. Common symbols included depicting kings larger than subjects to represent importance, painting halos around holy figures, and using rich colors like gold and blue to represent sacredness. Specific symbols were also used to represent biblical figures and events, like depicting the Virgin Mary in blue robes or Jesus as the Good Shepherd. Colors held symbolic meanings as well, with different hues representing concepts like love, suffering, and holiness. The placement and size of figures within a window's design further conveyed important aspects of the story or event depicted.