Galaxy S7/Edge gets Android 7.0, defaults to lower resolution
The Samsung Galaxy S7 and S7 Edge have just received an update to Android 7.0 Nougat. It isn't the most recent version (7.1.1) but it's a jump from Marshmallow. As part of the update process, it seems the update also sets the handset's natively QHD display to FHD resolution.
The default of the QHD (1440 x 2560) display to FHD (1080 x 1920) is the result of Samsung wanting to improve users' battery life. The display is able to be set as low as HD (720 x 1280) and as high as QHD, and if you want to change the resolution back to either of them according to your taste, you only need to go to the Display settings to do so.
The advantages of running at native QHD or downscaled are debatable. The display should still be using the same amount of power to be on, but the GPU will not need to work as hard to push a lesser amount of pixels to the screen (at the cost of fidelity). If you watch a lot of QHD videos, however, then you will notice more of a difference.