The Rule of Thirds is a technique used in visual artwork such as photography, paintings, and designs. A grid is broken into nine squares and placed on a picture and in order for a photo to be in thirds your object of interest my fall within a certain intersection of the squares. Typically a photo needs to be cropped to apply this rule. Usually the Horizon or a vertical object will help a line a photo into the thirds. This visually aids the spectators eye to automatically see the focus of the photo. Basicly you’re helping the people viewing your art see what you see.