Each of the pixels on the EOS R5’s 45-megapixel sensor is made up of two photosites. In Dual Pixel RAW mode, two images are captured every time you shoot: one with the left hand photosites; another with the right. By comparing the very slightly different views seen in each of these images, a depth map can be embedded in the RAW file, meaning subtle adjustments can be made to the end result based on this 3D data.
Dual Pixel RAW adjustments are made using the freely available Canon Digital Photo Professional software. New with EOS R5 is the ability to apply Portrait Relighting and Background Clarity in camera.