Use this tag on questions about the copyrighting process and principles. Questions solely pertaining to general copyright are off topic.
Copyrighting is the principle of assigning automatic rights over their work to content creators. These rights are in place to prevent work being stolen and used without permission for uses which perhaps the author doesn't want it to be used for.
This is very relevant to open-sourcing, because the principle of adding an open-source license is to give back to the community many of the freedoms (though not all) that they would enjoy without copyright.