Let’s say you have the BuzzFeed app opened, swipe up the dock, then press and drag another app from the dock all the way to the edge of the screen.
That’s it! This is also known as split view.
If you would like to change the size of each side, simply drag on the handle in the middle.
You can also move contents from one side to the other by just dragging it.
On the other hand, if you want to change either side of the app, pull up the dock once again and drag another app to either side you want the app to appear.
And if you would like to return to the single screen app, drag the handle all the way to the end of the screen.