In back-wired recepts the screw and backplate still provide pressure for the termination, rather than an internal spring/catch. But they will look similar in having holes in the back to insert the wires.
GFCI's usually have provisions for two back-wired conductors per screw.
These are considered quite dandy in my opinion whereas backplugged (spring/catch type) are not.
-Virgil Residential/Commercial Inspector 5 Star Inspections Member IAEI
