What is HDR?
HDR stands for High Dynamic Range. It is necessary because while the human eye can adjust to see varying stops of lights, the camera can only chose one exposure to capture for each scene. So when it comes to photographing homes, in order to balance the brighter exterior with the darker interior, multiple images of the same scene is taken at increasing exposures and blended together in order to create one perfect photo like the examples below.
HDR blending is a delicate process and if not done right, the resulting image can end up looking oversaturated and grungy like the photos on the left below. If done correctly, it will look natural with just a touch of color and pop like the photos on the right below.