"C-" (control) means "hold down Ctrl key"

"M-" (meta) means "hold down Alt/Option key", or "press and release Esc key"

Category	Command	Keystrokes	Mnemonic
Start/Stop	start emacs (in Terminal)	emacs -nw
	exit emacs	C-x C-c
Files	read a file into Emacs	C-x C-f	find
	create a new file (name it as if it exists)	C-x C-f	find
	insert a file	C-x i	insert
	save	C-x C-s	save
	save as ...	C-x C-w	write
Cursor Motion	forward (right arrow)	C-f	forward
	backward (left arrow)	C-b	backward
	down (down arrow)	C-n	next
	up (up arrow)	C-p	previous
	jump to start of line	C-a	a = start alphabet
	jump to end of line	C-e	end
	jump to start of buffer (a "buffer" holds a file's text or a directory listing, etc.)	M-<	< = left
	jump to end of buffer	M->	> = right
Cut, Copy, Paste "kill" = "cut", "yank" = "paste"	delete current character	C-d	delete
	delete previous character	Backspace
	kill to end of line (twice to include newline)	C-k	kill
	set mark; "region" is between invisible "mark" and "point" (cursor)	C-SPACE
	kill region	C-w
	copy region	M-w
	yank back last thing killed	C-y	yank
	replace last yank with previous kill	M-y
	kill, yank rectangle region	C-x r k, C-x r y
Formatting	indent current line	TAB
	indent buffer	M-x indent-region
	fill paragraph	M-q
Error Recovery	abort partially typed or executing command	C-g
	undo an unwanted change	C-_ or C-/	undo
	restore buffer to original contents	M-x revert-buffer
The Minibuffer	complete as much as possible	TAB
Type C-x ESC ESC to repeat the last command that used the minibuffer. Then the following keys are defined.	previous minibuffer command	M-p	previous
	next minibuffer command	M-n	next
Multiple Buffers	make one buffer	C-x 1	one
	split buffer vertically	C-x 2	two
	split buffer horizontally	C-x 3
	switch to other buffer	C-x o	other
	Resize buffers: wider, narrower, taller (Each can use a prefix argument via C-u; e.g. C-u -10 C-x ^ goes taller -10 lines.)	C-x } C-x { C-x ^	right left up
Buffers	list buffers	C-x C-b	buffer
	visit a buffer from the buffer list	type SPACE (or f) on the buffer's line	find
	close a buffer	C-x k	kill
	go to shell buffer	M-x shell
Incremental Search Then type a word for which to search. Use C-s or C-r again to repeat the search in either direction.	search forward	C-s	search
	search backward	C-r	reverse
	regexp search forward	C-M-s or C-M-S
	regexp search backward	C-M-r or C-M-R
	exit search	Enter
	find all occurrences	M-x occur
Query Replace yes = "y" or SPACE, no = "n"	interactively replace text	M-% (or M-x query-replace)
	interactively replace regexp	M-x query-replace-regexp
Regular Expressions for search and query replace	See this summary of regular expressions and the manual
Directory Editor to list and manage files find directory (C-x C-f . ), then "?" for help	delete (rather, mark for deleting)	d
	undelete (rather, unmark) a file	u
	expunge (delete files marked for deleting)	x
	find	f
	rename	R
	copy	C
	create directory	+
	refresh directory	g
R	start R buffer	M-x R
	run one line of R code	C-c C-n	from within a ".R" file
	run chunk of R code	C-c C-c	chunk
	run buffer of R code	C-c C-b	buffer
	show documentation for R mode (ESS)	M-x help Enter m
Help	help	M-x help	help
	show function a key runs	M-x help Enter k [key sequence]	key
	tutorial	M-x help Enter t	tutorial

To learn more, visit Emacs Tour, Emacs Reference Manual, Emacs FAQ.

• MacOS users for whom the alt/option key does not work should use Terminal's Edit menu to select "Use Option key as Meta key".
• To fix C-SPACE not working on a Mac: In "System Preferences > Keyboard > Shortcuts > Input Sources", check both "Select the previous input source ^Space" and "Select the previous input menu ^\Space"
• To fix C-SPACE not working on MobaXTerm on Window: In "Settings (on the right) > Keyboard Shortcuts", click "Execute a Macro", which is set to "Ctrl+SPACE"; use the bottom-right menu to change it to "<None>".
• To fix dark-on-dark in emacs, add this line to your ~/.emacs file:
  (setq frame-background-mode 'dark)
  Save the file, exit emacs, and start it again.