It is a small hole (usually about a half-inch wide) located at the bottom center of the freezer compartment or at the back of the fridge section. This hole leads to a tube that snakes down the back of the appliance and empties into a drip pan near the compressor.
If you see ice, You will puncture the refrigerant lines and kill your fridge. Use a hair dryer or a pan of hot water to melt the ice gently. refrigerator defrost drain