is about the editor operations cut, copy, and paste as they apply to Emacs. In Emacs, cut is called "kill" and paste is called "yank" (but Emacs enhances the standard cut and paste behavior).
Emacs manual and help (documentation strings) generally use the terms killing
and yanking
for cutting and pasting. The manual speaks of copying, cutting, and pasting when it mentions interoperating with the underlying operating system's clipboard using the primay-selection and the secondary-selection.