The difference between the Expressif Systems part number ESP32-S2-DEVKITM-1 and ESP32-S2-DevKitM-1R is the “R” suffix calls out the part has a " PSRAM die inside".
1965-ESP32-S2-DEVKITM-1-ND
1965-ESP32-S2-DEVKITM-1R-ND
The difference between the Expressif Systems part number ESP32-S2-DEVKITM-1 and ESP32-S2-DevKitM-1R is the “R” suffix calls out the part has a " PSRAM die inside".