A-Dock is a bit like Mac OS X's dock. It acts as an application switcher and an application launcher
It's separated in 3 zones :
your favorite applications you've added by drag&drop (left part)
the other applications running on your computer (middle part)
the trash (right part)
You can minimized A-Dock to just a small bar to save space on your screen. This bar auto-pops out when you move the mouse inside and minimizes again when you move the mouse outside. But of course if you have a big screen, you can leave it opened....
A-Dock is stuck to the screen edges. Switching your monitor resolution will not move the dock to a place you don't want like the App Switcher does everytime I play Quake 2. The dock can be positionned everywhere on the sceen edges. Just grab it and drag it !!