Except that in this scenario, the application is still running, it just has no documents open. It's a nice thing to have because you can close all the documents

Except that in this scenario, the application is still running, it just has no documents open. It's a nice thing to have because you can close all the documents in say Word, do some other work, and then when you need to open Word again, it's there ready to go without having to load again. The Mac seems to do a better job of having apps hanging out in the background than Windows does.