4:   What do these mean: etc/SERVICE, src/config.h, lisp/default.el?
  
  These are files that come with GNU Emacs.  The GNU Emacs distribution is
  divided into subdirectories; the important ones are `etc', `lisp', and
  `src'.
  
  If you use GNU Emacs, but don't know where it is kept on your system,
  start Emacs, then type "C-h v exec-directory RET".  The directory name
  displayed by this will be the full pathname of the installed `etc'
  directory.
  
  Some of these files are available individually via FTP or e-mail, see
  question 20.  All are available in the source distribution.