The Ribbon, which is part of the Microsoft Office Fluent user interface, is designed to help you quickly find the commands that you need to complete a task. Commands are organized in logical groups that are collected together under tabs. Because each tab relates to a type of activity, such as writing or laying out a page, it is not possible to customize the Ribbon without using XML and programming code.
The following is the Insert tab on the Ribbon in Microsoft Office Word 2007.

Things you can't do
Things you can do