Could someone explain hash tag usage for deeplinking ajax applications?

I am currently trying to full appreciate how and when to use hash tags in urls when building an ajax powered website. There seems to b开发者_JAVA技巧e a distinct lack of reading material on the web regarding this technique and as such I don't feel like I've got a good handle on it.

Could someone explain in the simplest terms how the hash tag can be used in urls to enable things like loading pages via ajax.

Thanks

You might want to take a look at Google's Making AJAX Applications Crawlable website.