There are lots of ways to move data between or within graphical windows! But the list is shrinking
- clipboard - cltr-c / ctrl-v
- drag and drop - mouse selection, mouse drag
- primary - mouse selection -> middle click (or shift+ins); moves text cursor
- secondary - ctrl+select (alt+select in emacs); secondary doesn't move text cursor. largely forgoten. motif, patched gtk; not in qt, tk, mainline gtk, etc
- cut-buffer - deprecated everywhere. set by application using X11 window property for state