Single Door refrigerator
Single door refrigerators contain both the fridge and the freezer under the same door.
Double Door refrigerator
Double door refrigerators have separate cabinet for fridge and freezers. Both the fridge and freezer can be accessed through separate doors.
Single door refrigerators have less space due to the freezer box. Freezer box takes up the top space of the fridge
Double door refrigerators have more storage space and wider shelfs in both fridge and freezer. They are usually taller than single door fridge.
Single door fridge consumes less power due to reduced capacity and single cooling path for both the fridge and freezer.
Double door fridge consumes more power due to the large storage space and separate cooling for the fridge and freezer.
Single door fridge has less features compared to double door. They do not have features like frost free and the freezer can not be converted
Double door fridge has features like frost free and the freezer can be converted into a fridge to increase the capacity.
Double door fridge is only required if you need a fridge with capacity more than 200 liters. Otherwise, single door will suffice.