Many refrigerators have an automatic defrost feature, though not all. In standard-size refrigerators, it is usually intended for the freezer only. However, it works for the entire unit of mini refrigerators.
Refrigerators with the auto-defrost feature are beneficial since nothing needs to be unplugged in order to defrost it. All food can remain in its original place, though an excessive amount of items in the freezer should be removed. Without this auto-defrost feature, all foods must be removed from the entire unit, and it needs to be unplugged for a certain period of time. This is called manual defrosting, and it requires a lot more work and time to complete.