DNG and RAW are not the same thing. DNG is a file format created by Adobe to hold image data. It can hold both RAW and non-RAW data.
Apple uses DNG to hold RAW data for iPhones, as do some other camera manufacturers. Most, however, have their own proprietary RAW image format.
“RAW” can means two things: a) sensor data that has been minimally processed by the camera and b) a quasi file format. There is no file format called “RAW” — a RAW file is simply a file that contains RAW data. Each RAW decoder has code to read the various manufacturer file formats to extract the RAW sensor data + metadata.