This document discusses the visual element of line. It defines line as an edge, contour, path, or directional signal that directs our vision. Line is important for defining and describing the visible world. There are several characteristics of lines. Lines can be straight, curved, thick, thin, solid, broken, and have various surface qualities. Lines are also used for systems of notation like letters, maps, music, and barcodes. Lines can form patterns, create the illusion of dimension and movement, and indicate style, age, and mood. Overall, line is a powerful visual element for expression that conveys ideas, attitudes, and psychological meanings.