The strategic use of lines can greatly enhance a composition. Proving their importance, many classifications of lines have been established in the art world with each type having unique qualities and strategic uses. Vertical lines imply strength, dominance and stature. Images of tall buildings, cityscapes and full- length portraits are a few examples. Horizontal lines imply rest, leisure and sleep. When a person lays down to take a nap, it's done in a horizontal position. Diagonal lines imply movement and speed. When diagonal lines are presented in a picture, the action seems to whiz through from one corner of the photo to the other. Receding lines lead the viewer to the point where the lines converge or leave the composition. Converging railroad tracks is the quintessential example.