The most used selection is the PRIMARY
selection, and is used when the user selects some data. The CLIPBOARD
selection is used when the user selects some data and explicitly requests it to be "copied" to the clipboard, such as by invoking "Copy" under the "Edit" menu of an application. An associated request of "Paste" results in the data of the CLIPBOARD
selection being used.
At the level of the core protocol, the PRIMARY
and CLIPBOARD
selections do not differ. But the xclipboard
client makes them behave differently. In particular, when another client asserts the ownership of the CLIPBOARD
selection, this program requests and displays it in a window. Any further request for this selection are handled by xclipboard
. This way, the content of the selection survives the client having copied it.
Read more about this topic: X Window Selection