This is a format that is used for RAW images on Nikon cameras. It contains metadata about the lenses that were used to take the photo, capture settings, and other conditions. It provides a record of the data array obtained by the camera sensors through the lens. It allows you to edit the sharpness, colors, and tones with no loss to the content or quality of the image, which is something that cannot be done with compressed images. It supports 12- and 14-bit images.
BMP is format for storing bitmap images. In this format, you can only save bitmaps monolayer. For each pixel in different files may come different number of bits. The latest versions of the BMP has the ability to control color. In particular, you can specify the endpoints perform gamma correction and embed color profiles ICC.