What the hashbang does is update the URI in such a way that it’s possible to bookmark/share a URI (assuming you’ve coded your app properly). It is however just a stopgap measure until pushstate turns up - that way we’ll be able to have URIs that encode the document/state reference in the proper part, not the fragment.

Actually, you are right with regards to the bang pash of hashbang - that’s just a Google defined way of letting them access the content.