Both are series brands of MEAN WELL Power Supply, with different uses and materials.
NDR-120 is an economical and thin 120W rail-type power supply that complies with German industrial standards and is suitable for installation on TS-35//5 or TS-35/15 rails.
MDR is a plastic shell. MEAN WELL switching power supply products are used in industrial automation control, equipment, power equipment, medical equipment, semiconductor refrigeration and heating, digital products and instruments and other fields.