Just to be clear on what it does, it helps capture pictures more clearly and evenly by taking three pictures at different exposures and putting them together for the best possible output. (techtimes.com)
This situation presents a range of different exposures, and while the human eye automatically adjusts for the various levels, the camera will have a hard time making sense of it all. (realtormag.realtor.org)
Also, you can switch between different exposure mode with a mode dial which is very handy when you're shooting pictures outside. (apktechnical.com)