The lines themselves would be rays because they each have a starting point and no defined end. The direction of those rays would be the vectors which would be traveling 180 degrees in the opposite direction relative to their individual starting positions.

Of course, the example is flawed anyway for a number of reasons. But yes, you are correct. The “lines” are actually rays

Two parallel lines can coexist on a plane heading in opposite directions (vectors) without being the same line. They are traveling 180 degrees relative to the other line’s vector, not a fixed point on one of the lines