conservation of energy vs law of conservation of energy

conservation of energy and law of conservation of energy both are nouns.

Word	Noun	Adjective	Verb	Adverb
conservation of energy	Yes	No	No	No
law of conservation of energy	Yes	No	No	No

As nouns, conservation of energy and law of conservation of energy are synonyms defined as:

conservation of energy and law of conservation of energy: the fundamental principle of physics that the total energy of an isolated system is constant despite internal changes

Other synonyms of conservation of energy include first law of thermodynamics.

conservation of energy (noun)	law of conservation of energy (noun)
the fundamental principle of physics that the total energy of an isolated system is constant despite internal changes	the fundamental principle of physics that the total energy of an isolated system is constant despite internal changes