One solution:
The lines only intersect in one place.
No solution:
This means the lines never meet. The only way this is possible is if the lines are parallel. Actually, that's literally the definition: parallel lines never meet.
Infinite solutions:
The lines are one. They overlap completely, that's why all the points on the lines are shared.
And as for what you've learned, I can't help you there. But:
-lines with the same slope are always parallel-- unless the y-intercept is also the same, then they are the same line.
-if the slopes of two lines are opposite reciprocals, they will meet at exactly one point, and they are perpendicular.
hmm, those are the only two things I can think of at the moment. Hope I could help you!
