The Vanishing Tabs
One of the most important features is that there are additional "tabs" of tools that seem to randomly appear and disappear. It's not that random, it's based on what is selected in your document. In the three pictures below you'll see what is available on the tab bar based on whether or not the picture is selected.
In the first picture the cursor in in the text. As a result, the tabs end with the View tab. In the second picture a picture is selected so the Picture Tools --> Format tab is available. While it is available in this picture it is not the active tab. Click on the Format tab makes it active. See the third picture which has the Format tab active.
So the important thing to remember is to keep your eyes on the tab area in Microsoft Office. Tabs will appear to "come and go" but you need to be aware of what is selected in your document.
Hope this helps.


