refrigeration vs preservation

refrigeration and preservation both are nouns.

Word	Noun	Adjective	Verb	Adverb
refrigeration	Yes	No	No	No
preservation	Yes	No	No	No

As nouns, preservation is a hypernym of refrigeration; that is, preservation is a word with a broader meaning than refrigeration:

refrigeration: the process of cooling or freezing (e.g., food) for preservative purposes
preservation: a process that saves organic substances from decay

Other hypernyms of refrigeration include chilling, cooling, temperature reduction.

refrigeration (noun)	preservation (noun)
deliberately lowering the body's temperature for therapeutic purposes	the activity of protecting something from loss or danger
the process of cooling or freezing (e.g., food) for preservative purposes	an occurrence of improvement by virtue of preventing loss or injury or other change
	a process that saves organic substances from decay
	the condition of being (well or ill) preserved