The update is includes the include all the basic Android 7.0 Nougat features like New Multi-window allows the user to switch between apps with a double tap or run two apps side by side. More personalized settings and smarter notifications allow users to be more productive with less effort. It also includes the enhanced version of Doze.
The update weighs around 1.1 GB in size and rolling out over the air. So it might take some time to reach you. Meanwhile you can always check it by going into Settings > General > About phone > Update Center > System update > Check for update.