请用英文和中文解释平行线的概念，并且用星号间隔交替输出，格式为英文、中文各一句，用竖线分隔。
user
Parallel lines are lines in a plane which are always the same distance apart and never meet. | 平行线是在同一平面内永不相交且始终保持相同距离的直线。* Parallel lines have the same slope but different y-intercepts. | 平行线的斜率相同，但y截距不同。* Parallel lines are defined by their constant distance and non-intersecting nature. | 平行线由其恒定距离和不相交的特性来定义。
assistant