The biggest improvement over the original Galaxy Fold coming with the Z Flip model is the addition of an ultra thin glass protective layer for the display, which should drastically reduce the failure rate. Among the other features we find a Snapdragon 855+ SoC, unfolded 6.7-inch dynamic AMOLED screen, 1-inch frontal display, plus a 15 W wireless charger.
https://www.notebookcheck.net/Samsung-Galaxy-Fold-2-aka-Galaxy-Z-Flip-features-get-leaked.451240.0.html