A leading line paves an easy path for the eye to follow through different elements of a photo. Usually they start at the bottom of the frame and guide the eye upwards and inwards, from the foreground of the image to the background, typically leading toward the main subject.
Read more: http://digital-photography-school.com/how-to-use-leading-lines-for-better-compositions#ixzz2ZPan40BX
