The Microsoft Office button
Many of the most valuable features in previous versions of Microsoft Office were not about the document authoring experience at all. Instead, they were about all the things you can do with a document: share it, protect it, print it, publish it, and send it. In spite of that, previous releases of the Microsoft Office applications lacked a single central location where a user can see all of these capabilities in one place. File-level features were mixed in with authoring features.
The Office Fluent user interface brings together the capabilities of the Microsoft Office system into a single entry point in the UI: the Microsoft Office Button. This offers two major advantages. First, it helps users find these valuable features. Second, it simplifies the core authoring scenarios by allowing the Ribbon to focus on creating great documents.