H-field lines originate from the north pole and terminate at the south pole of a magnet. There is a distinction between H-field and B-field lines, particularly inside a magnet, where they point in opposite directions. Outside a magnet, H-field lines align with B-field lines. The relationship between B, H, and magnetization (M) indicates that while B-field lines are continuous, H-field lines can vary in density based on the magnet's properties. Overall, the discussion clarifies the behavior and directionality of magnetic field lines in relation to magnet poles.