So here's a sketch of a simple bar magnet. Bar magnets have a negative pole at one end and a positive pole at the other and the convention is to draw field lines from negative to positive. So here's a field line. Here's another one. In fact, field lines are actually continuous. We can draw them as loops like this. There's an infinite number of them and they're parallel to each other. So here's another one. And there's our bar magnet!