What is difference between nw and nnw heading?

The difference between NW (Northwest) and NNW (North-Northwest) headings lies in their specific compass bearings. NW corresponds to a direction of 315 degrees, while NNW points to 337.5 degrees. Essentially, NNW is slightly more northward than NW, making it a more precise direction. Both headings are used in navigation and meteorology to indicate wind or travel directions.