Th new search field is designed to help users more easily navigate the commands in the Office Web Apps ribbon.
Microsoft calls the new search technology "Tell Me." Microsoft specifically noted the addition of the Tell Me box to Word Web App, but it also has been added to Excel Web App. It's not clear when Tell Me will come to Microsoft's PowerPoint Web App and OneNote Web App.
Office Web Apps can be used in a variety of browsers — including Internet Explorer, Chrome, Firefox and Safari — and on different operating systems and form factors (PCs, tablets, and smartphones).