You can be watching a video or checking out a document, and chatting with comments below them, for example, but the possibilities are endless, as you can mix and match any two apps on the phone.
There were hints that this multi-windows mode will be ported to the Samsung Galaxy S III as well, despite that it has a smaller screen than the huge 5.5-incher on the Note II. We'd say 4.8" is still big enough for some serious multitasking, and are glad that it's coming to the S III.
Apparently this multitasking regime will arrive to the phone with the next Android 4.1.2 update, judging from some leaked screenshots that display a trial update for a Galaxy S III on an Israeli carrier. The split screen mode is also coming to the gallery, where you have the albums/folders on the left, and their content on the right, just like on the Note II.
The source says the 4.1.2 update for the Galaxy S III should be coming before year-end, and we've heard December mentioned before, so not much waiting left.