In comics, motion lines (also known as movement lines, action lines, speed lines or zip ribbons) are the abstract lines that appear behind a moving object or person to make them look like they're moving quickly. The use of motion lines in art is similar to the lines showing mathematicalvectors, which are used to indicate direction and force. A similar effect is found in long-exposure photography, where a camera can capture lights as they move through time and space, blurred along the direction of motion. They are highly predominant in Japanese manga.
Motion lines added with photo-editing software, to imply motion