clipboards
Cut-and-paste.
X distinguishes primary and visual clipbaords. In addition, Emacs has the kill-ring. and shells keep their own kill ring. This can lead to some interesting situations.
n GUI Emacs and EXWM, the last item of the visual clipboard becomes the "yankable thing" but isn't the top of the kill-ring. Emacs' treatment of non-Emacs-controlled clips is mediated by the variables interprogram-cut-function
and interprogram-past-function
.
Shells and remote shells cna also be variously configured to pass clips through or not; generally, they too don't push interprogram clips to kill rings if they are maintaining them.
Fun little corner of terrible congealed glue in the works.