refrigerator vs fridge

refrigerator and fridge both are nouns.

Word	Noun	Adjective	Verb	Adverb
refrigerator	Yes	No	No	No
fridge	Yes	No	No	No

As nouns, fridge is a hyponym of refrigerator; that is, fridge is a word with a more specific, narrower meaning than refrigerator:

refrigerator: white goods in which food can be stored at low temperatures
fridge: a refrigerator in which the coolant is pumped around by an electric motor

Other hyponyms of refrigerator include cooler, ice chest, electric refrigerator.

refrigerator (noun)	fridge (noun)
white goods in which food can be stored at low temperatures	a refrigerator in which the coolant is pumped around by an electric motor