"Aero Shake", first introduced with the Windows 7 operating system, is a way to minimize all open windows on your desktop except the one that's "shaken." It's easy to use: just grab the window you want to isolate by clicking in the title bar -- that's the bar at the very top of the window, which will normally have a red "X" in the upper right-hand corner. Grab it by clicking and holding the left mouse button.
Now, just shake your mouse back and forth quickly, while continuing to hold down the button. All other windows should automatically shrink down, but will still be available to use. To bring those windows up again and restore your desktop, do the exact same shake routine again.
Aero Shake takes a bit of practice to get used to, but if you do it a few times, you'll quickly get the hang of it.