Apple introduced the concept of "full-screen application" in Mac OS X Lion:
OS X Lion's entire system supports gorgeous full-screen applications, making it possible to take full advantage of every inch of the MAC display screen. You can enable multiple full-screen applications and multiple standard-sized programs to be turned on and easily switch between full screen and desktop.
While "full-screen mode" can be a lot of benefits, it's a bit unbearable to have access to the system Dock in full-screen mode ... In fact, Apple has already prepared a solution for everyone: in full screen mode, move the mouse pointer to the Dock bar ... No response? Continue to move down ... See! The Dock bar is out!
PS: For the habit of placing the dock bar on the edge of the children's shoes, remember extrapolate, in short, the mouse dock in the direction of the mobile ... Move again ...