OS X Yosemite: Take apps full screen
In many apps, you can expand the window to fill your entire screen. While in full-screen view, swipe to see another app’s full-screen window, to see your desktop, or to see a space you created.
Expand to full-screen view: Click the green full-screen button in the top-left corner of an app window, or press Control-Command (⌘)-F.
Move between windows in full-screen view: Swipe left or right on a trackpad or Magic Mouse. For more information, see Learn trackpad and mouse gestures.
Return to standard view: Move the pointer to the top-left corner of the screen, then click the green full-screen button again, or press Control-Command (⌘)-F.
You can also double-click an app’s title bar to expand the app window to fill the space between the Dock and the menu bar. If the Dock is on the side of your screen, the window expands to fill the space below the menu bar and to the side of the Dock. You can also Option-click the green full-screen button in the top-left corner of an app window.
To return to standard view, double-click the title bar, or Option-click the green full-screen button again.
If you double-click an app’s title bar, and the app minimizes into the Dock, the “Double-click a window’s title bar to minimize” option is set in Dock preferences. To instead expand the app window, choose Apple menu > System Preferences, click Dock, then deselect “Double-click a window’s title bar to minimize.”