X has a things called “selections” which are just clipboards.
There are 3 selections one needs to be aware of:
PRIMARY for mouse selections. This is where terminal emulators, for
example, will put stuff that gets selected, so this usually contains text
that was last selected/highlighted with a mouse. This content can usually be
accessed using middle mouse button.
This does means that selecting anything overwrites this clipboard.
SECONDARY - from the Arch Wiki:
SECONDARY is only used inconsistently and was intended as an alternate to PRIMARY.
It is just another option, no one uses it in particular
CLIPBOARD for Windows-style cut/copy/paste (explicitly pressing Ctrl-C
after selection, for example).
References:
Related:
xclip toolxsel toolTags:
#literature-note #linux #X11