In a word, focus.
In a another word, order.
Hana allows you to work without having to fight the urge to check the news, sports and other information you check regularly via your web browser.
Hana also allows you to bring all of your "work" web sites into one place. Hana brings order to your web working life!
But Hana is more than JUST focus, Hana is about context. Work in Hana. Play in Safari or Firefox.