Curved lines are lines that bend or change direction smoothly, rather than being straight. They can be found in nature, such as the shape of a rainbow or the outline of a leaf. Curved lines can vary in tightness and shape, from gentle arcs to sharp curves. In art and design, curved lines are often used to create a sense of movement and flow. They can evoke feelings of softness and elegance, making them popular in various styles, including graphic design and architecture. Curved lines help to create visual interest and can guide the viewer's eye through a composition.