1 Text filling and reformatting commands

Keystrokes	Command name	Action
(none)	refill-mode	Toggle refill mode, in which Emacs automatically reformats text.
(none)Options → Word Wrap in Text Modes	auto-fill-mode	Toggle auto-fill mode, in which Emacs formats paragraphs as you type them.
M-q	fill-paragraph	Reformat paragraph.
(none)Edit → Fill	fill-region	Reformat individual paragraphs within a region.

Remember that (none) in the first column means that you type M-x followed by the command name in the second column, then press Enter to run the command. There are no default keystrokes. To use the refill-mode command, type M-x refill-mode Enter.