The graphic qualities of lines are stronger than those of points. Different lines also have distinct associations. Horizontal lines have a more comforting effect than diagonals and a lot less than zig-zags. Strong, definite lines can express boldness. Thin, curving lines can express delicacy. But this is not always true in photography.
Diagonals are eye catching. They are highly active and unresolved. Horizontal lines that run away from the eye converge in a photograph, thus giving the illusion of depth and distance. Wide angle lenses like the 24mm create diagonals to give the viewer the illusion they are part of the scene. Telephotos compress lines to make them appear parallel and images simpler.