buffer is used to hold the text of the message. When you ask for a
command's documentation, that appears in a buffer named @file{*Help*}.
+ Buffers exist as long as they are in use, and are deleted
+(``killed'') when no longer needed, either by you (@pxref{Kill
+Buffer}) or by Emacs (e.g., when you exit Emacs, @pxref{Exiting}).
+
Each buffer has a unique name, which can be of any length. When a
buffer is displayed in a window, its name is shown in the mode line
(@pxref{Mode Line}). The distinction between upper and lower case