The format has a TIFF-image structure. It is generated by Canon cameras. The CR2 photo is stored in an uncompressed form and allows you to edit such settings as white balance, exposure, and other settings for photos that were already taken. It is the successor format to CRW, which was used in previous generation Canon SLR cameras.
This format is used for storing bitmap images with improved levels of color and brightness performance. It combines exposures to record darker tones in the shadows or detail in the lighter areas of a given photo. HDR is able to combine multiple images with different levels of light distribution. It is used to create rich images.