cua-mode is an interactive autoloaded compiled Lisp function in `cua-base.el'.

It is bound to <menu-bar> <options> <cua-emulation-mode>, <menu-bar> <options> <cua-mode>.

(cua-mode &optional ARG)

Toggle Common User Access style editing (CUA mode).
With a prefix argument ARG, enable CUA mode if ARG is positive,
and disable it otherwise. If called from Lisp, enable the mode
if ARG is omitted or nil.

CUA mode is a global minor mode. When enabled, typed text
replaces the active selection, and you can use C-z, C-x, C-c, and
C-v to undo, cut, copy, and paste in addition to the normal Emacs
bindings. The C-x and C-c keys only do cut and copy when the
region is active, so in most cases, they do not conflict with the
normal function of these prefix keys.

If you really need to perform a command which starts with one of
the prefix keys even when the region is active, you have three
- press the prefix key twice very quickly (within 0.2 seconds),
- press the prefix key and the following key within 0.2 seconds, or
- use the SHIFT key with the prefix key, i.e. C-S-x or C-S-c.

You can customize `cua-enable-cua-keys' to completely disable the
CUA bindings, or `cua-prefix-override-inhibit-delay' to change
the prefix fallback behavior.