The format is designed for Kodak cameras to store uncompressed RAW images in their original form without auto color and white balance correction. The file has a TIFF-structure that allows you to edit the color temperature and exposure of the finished image without losing information and quality, which is something that cannot be done with JPEG format images.
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.