Android N update: strange icon I've got a Samsung Galaxy S6 edge and yesterday I updated it to Android 7.0.
It's really easy to use and I really like it. 
But I have a question: In the notification bar there is an icon that I never seen before.

Here is the screen:

 

I know it's a stupid question but please, I've got to understand what it is.
That symbol represents that the data saver is on.

Data saver prevents apps from using data in the background (when you are on a mobile network, not WiFi), saving you mobile data and battery. Go to quick settings and toggle the data saver switch if you want to turn it off.