Frequently Asked Question

What do :w, :q, :wq, and :q! actually do?

All four are ex commands, entered by pressing : in normal mode, which drops you into the command-line at the bottom of the screen. :w writes the current buffer to disk, using the filename Vim already knows about. You can pass a different filename (:w other.txt) to save a copy, or a range (:5,10w extract.txt) to write only those lines.

:q quits the current window. If the buffer has unsaved changes, Vim refuses and prints E37: No write since last change. :wq is the common combination, write then quit, and :x is almost the same except it only writes if changes were made (slightly nicer for file modification timestamps). The shortcut ZZ in normal mode is identical to :x.

:q! is the force-quit: discard any unsaved changes, leave immediately. The ! after almost any Vim command means "I really mean it" and overrides safety checks. Use :wq! to force a write even when the file is read-only (Vim will use chmod tricks if it can), and :qa! to quit all open windows discarding changes everywhere.