Think of Awesomebox like a versioned CDN - you can push any HTML, CSS or JS, and then invite anyone to view, comment and annotate it.
It's different from a widget in that Awesomebox gives you infinite staging environments - if you push 10 different ideas, and then invite a few people, they can easily switch between different versions without you having to manage multiple servers. In our experience, this is really important when working through new ideas or designs with clients or managers.
Does that help answer your question? Happy to explain more if not.