High Dynamic Range aka HDR photography is a process that combines multiple photos (exposures) into one single image. By doing so, it gives the final image a greater range of contrast between the brightest and darkest spots in a photo. Simply put, HDR takes the dark spots and makes them more visible, and brings the bright spots down so you can view the details better. HDR photos are particularly useful in real estate photography, as they can help to show off a property with hard lighting in a more evenly/consistent final image. HDR method allows photographers to capture a greater range of detail than what is possible with a single exposure - this is why it became the industry standard for a long time.