A “buffer” is the basic building block of the Emacspeak desktop. Any information presented by Emacs is placed in a “buffer”. For example, when perusing this manual within Emacs, the “file” containing the documentation is presented in a “buffer”. All information objects such as WWW pages, email messages, output from user interaction with command-line shells etc., are presented by Emacs in individual “buffers”.
Buffers provide a base level of user interaction; Emacs derives its power by allowing applications to specialize buffers to enable specific types of user-interaction that is optimized for a specific class of information.