The Jargon File continues:
. . . [EMACS] was originally written by Richard Stallman in TECO under ITS at the MIT AI lab; AI Memo 554 described it as "an advanced, self-documenting, customizable, extensible real-time display editor".
When running under X, Emacs has a menu bar, but I almost never use the mouse. Why? Because using Emacs with the keyboard is extremely fast---literally everything has a keyboard shortcut.
It would not be productive to list all the keyboard bindings here. There are a couple of printable reference sheets linked from the course web page. Instead, I will explain how you can get help within Emacs---this is what makes Emacs a "self-documenting" text editor.
Emacs uses many key combinations involving the Control and Meta keys. Such key combinations are denoted C-x (Control-x (lowercase)) or M-x (Meta-x). On keyboards that don't have Meta, Alt is usually an acceptable substitute. If Alt doesn't work, ESC-x is equivalent to M-x.
A sequence of key presses is written like C-a C-b M-x, which would mean do the three actions in sequence.
C-x C-c: Quits Emacs.
C-g: Cancels the current action.
C-h: Help. Hitting this will display a short message in the minibuffer: C-h (Type ? for further options).
C-h t: Built-in interactive tutorial. Some people don't like this tutorial, but some people find it helpful.
C-h b: Key bindings. This lists all key bindings that are valid for the current mode. Note that key bindings change from mode to mode!
C-h a: Command apropos. After hitting C-h a you can type a symbol and a window will appear that lists all symbols and functions that match that phrase.