GNU Info User's Guide

(1)

Of course, you can specify both the file and node in a --node command; but don't forget to escape the open and close parentheses from the shell as in:

info --node
'(emacs)Buffers'

(2)

M-x is also a command; it invokes execute-extended-command. See section 'Executing an extended command' in the GNU Emacs Manual, for more detailed information.