Lines, be they straight or curved, real or implied, can be strong elements in an image. They can serve to focus the viewers attention on the main subject, provide depth and perspective, lead the eye around the various components of an image, or even be the primary element. Careless use can also drag the viewer's eye to the edge of the photo and beyond in search of something interesting to look at. Their use can be cliched, but they can create interesting relationships between the various elements in a photo and add strength to a composition.
