Push wire terminals.
The BC Switched Lampholder is a standard lampholder used on table lamps. It has a push bar switch and a 10mm Base in the cap or base to fix to a 10mm stud. The White BC Switched Lampholder has a cap that snaps onto the body so it does not cause the wire to twist.
The terminals are push wire so are not a screw terminal and the wire is just pushed into a terminal clamp. This is designed for wires that have a crimp on or are soldered.