NEF is a format for original, raw graphic files created by Nikon technology. Accordingly, the developer of the format is also the specified company. The name of the format is an abbreviation for Nikon Electronic Format. At the same time, NEF format files received by Nikon cameras of different models can have a different structure, so compatibility is not guaranteed. Nikon's graphic editors are geared towards supporting specific camera models. When creating a file, the data comes directly from the matrix. NEF files are of good quality and contain metadata, and therefore take up a lot of space.
PNG is a raster image format developed by PNG Development Group. The name PNG is an abbreviation for Portable Network Graphic. This image format is used primarily on the Internet for posting on web pages, since PNG files use Deflate compression without losing quality. The development of this format was undertaken in order to replace the GIF format, to which there were many complaints. PNG's image quality and specifications were much better, but unlike GIF, it does not support animation and uses the CMYK palette.