Making Windows Active

  When you want to work with a window, you must make it
  active or give it input focus.  By default an active window
  moves to the front of the stack of overlapping windows, and
  its window frame is highlighted.  Any keystrokes you type
  appear in this window.  When you make another window
  active, the new window is given input focus.  Only one
  window can have input focus at a time.  To make a window
  active:

  1.  Point to a location in the window or window frame.

  2.  Click MB1.

                                Note

      To make a window active from an icon, double-click

      MB1 on the icon.