When the close button on a window's title bar is clicked the window no longer displays on the desktop and the recessed window button in the taskbar button area changes to a nonrecessed button is this?

This behavior indicates that the window has been closed, which typically means it is no longer active or visible on the desktop. The change from a recessed to a non-recessed button in the taskbar signifies that the application is no longer running or minimized. If the application is still running in the background, it may remain active but not visible. This functionality is common in most graphical user interfaces.