Freezer has a temperature below freezing point (0 degree F) while refrigerator has a temperature of 40 degree F. At freezing point, the enzymatic activities stop thus meat and meat products that have very less shelf life are stored in the freezer. Frozen food can be stored for months inside the freezer. In case of a refrigerator the enzymatic activities still take place and it is not used for storage purposes.
Thus, uncooked hamburger meat can be stored in a freezer for months rather than in a refrigerator.