A "line" is a straight path that extends infinitely in both directions, having no thickness. In geometry, it is often represented by two points, like A and B, which help define its position. Lines can be horizontal, vertical, or diagonal, and they are fundamental in creating shapes and figures, such as triangles and rectangles. In everyday life, a line can also refer to a queue of people waiting for something, like at a grocery store or a concert. Lines help organize and manage crowds, ensuring that everyone gets their turn. Whether in math or daily activities, lines play an essential role in structure and order.