A line is a mark made by a moving point and having psychological impact according to its direction, weight, and the variations in its direction and weight. It is an enormously useful and versatile graphic device that is made to function in both visual and verbal ways. It can act as as a symbolic language, or it can communicate emotion through its character and direction

Line is not necessarily an artificial creation of the artist or designer; it exists in nature as a structural feature such as branches, or as surface design, such as striping on a tiger or a seashell.

It can function independently to suggest forms that can be recognized, even when the lines are limited in extent. This can be seen in drawings such as the Saul Steinberg illustration shown here, or in Alexander Calder's minimal wire sculptures, which convey a great deal of information about the figure with the most limited line.

Lines can be combined with other lines to create textures and patterns.  The use of line in combination results in the development of form and value, which are other elements of design.

However, line is not always explicit. It can exist by implication, as the edge of forms. As young children we usually begin drawing landscapes by making outlines for earth, sky, and other objects. Gradually we learn that objects do not have such outlines and we let color changes define the edges of shapes, creating implicit lines. Thus we can speak of a horizon "line," or the "lines" of a car or a fashion silhouette, even though we know there is no literal line present. For additional visual examples of