RTE box is a Reverse Tuck End box, which has top and bottom closing flaps on opposite sides of the box. They are cost-effective and able to be stacked closely together for convenience. However, they have a weak cut edge on the front panel. This can affect a tuck in this area, by causing it to run into the window material edge during closing.
During assembly, the box is popped open; the bottom and top flaps are then closed once the product is inside. Assembly time is generally faster and there is more flexibility in how contents are positioned.