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.
PNG is a raster graphic data storage format that uses lossless compression algorithm to Deflate. PNG was created as a free format to replace GIF. PNG supports three main types of raster images: grayscale image, a color indexed image and the color image. PNG format stores graphical information in a compressed form.