There are many combinations of wiring a typical humbucker using some of these variables.

1. Both coils wound in the same direction: Either clockwise or counter-clockwise.
2. Each coil wound in an opposite direction: One coil wound clockwise and the other wound counter-clockwise.
3. Both coils have the same top magnetic polarity: Both coils have South or both have North top magnetic polarity. The top of the coil is the side facing the strings.
4. Each coil has an opposite top magnet polarity: One coil is South top polarity and the other is North top polarity.
5. Now combine these with Series, Split and Parallel wiring.

As you can see, there are many multiple wiring combinations along with winding directions and magnetic polarity in each bobbin. With all the combinations you have many sounds to get from your humbucking pickup.