apart from being faster, smaller and less bugged, you mean?

you have, for example, tabbed browsing: instead of opening a window for each separate site, with firefox you can open links in a new tab (click right, open in a new tab). this means that all your browser windows are accessible as a single windows window, switching is much faster between views.

in firefox you have an inbuild popup ad preventer, no need to install anything.

in the browser there is a prepared google search place, no need to go to the google page.

in firefox you have an interresting new feature. some sites (more and more) are using something called RSS. try, for example, http://news.bbc.co.uk/ . in the lower right corner of the screen you'll see 'RSS'. click on it, and subscribe. this gives you a variable folder in your bookmarks, that updates itself whenever there's something new on the server.

FENCER, WINK WINK, when will BK be on RSS? WINK WINK

and a lot more, I'm still discovering too.