All toolbars in the program have their corresponding action also listed in the main menu. This standard tool bar buttons are ALL listed in the File menu of the application.
I'll discuss the buttons from left to right.
Cascade
Cascades all active windows (this means not minimized windows). Default MDI application option.
Tile vertically
Tiles all active windows (this means not minimized windows) vertically. Default MDI application option.
Tile Horizontally
Tiles all active windows (this means not minimized windows) horizontally. Default MDI application option.
Maximize
Maximizes the active child.
Minimize
Minimizes the active child.
Normalize
Normalizes the active child, i.e. that the active child will not be minimized nor maximized, but will have the 'default' window properties.