The ribbon is a set of toolbars at the top of the window in Office programs designed to help you quickly find the commands that you need to complete a task. Sometimes the ribbon can get hidden and it's hard to find. The quickest way to show the ribbon is to click on any visible tab, like Home, Insert or Design. You might also want to hide the ribbon to maximize screen space.
Show The Ribbon All the Time
You can set Office programs to keep all the tabs and commands on the ribbon visible all the time.
- At the top-right corner, click the Ribbon Display Options icon Ribbon icon
- Click Show Tabs and Commands
Show Only the Ribbon Tabs
You can set Office programs to show only the ribbon tabs, so you see more of your document, and you can still quickly switch among the tabs.
- At the top-right corner, click the Ribbon Display Options icon.
- Click Show Tabs
When you click a tab, you can see the commands and select the options you want. When you return to your document, the tab commands are hidden again.
Collapse The Ribbon or Expand It Again
You can collapse the ribbon if you need to see more of the document you are creating. To collapse the ribbon, double-click any of the ribbon tabs or press CTRL+F1.
To see the ribbon again, just double-click any ribbon tab, or press CTRL+F1.
If The Ribbon Isn't Visible at All
If the ribbon isn’t visible at all (no tabs are showing), then you probably have it set to Auto-hide. Click the More icon 
at the top right of the screen. This will temporarily restore the ribbon.
The More icon temporarily restores the ribbon. When you return to the document, the ribbon will be hidden again. If you want to keep the ribbon displayed, see the steps above to Show the ribbon all the time.