I learned that GNU Emacs Manual
Most major modes fall into three major groups. The first group contains modes for normal text, either plain or with mark-up. It includes Text mode, HTML mode, SGML mode, TeX mode and Outline mode. The second group contains modes for specific programming languages. These include Lisp mode (which has several variants), C mode, Fortran mode, and others. The third group consists of major modes that are not associated directly with files; they are used in buffers created for specific purposes by Emacs. Examples include Dired mode for buffers made by Dired (see Dired), Message mode for buffers made by C-x m (see Sending Mail), and Shell mode for buffers used to communicate with an inferior shell process (see Interactive Shell).
Most major modes fall into three major groups of Text, Programming and File.
How could I retrieve a list of all the major modes equipped with my emacs.
auto-mode-alistand some are not defined with