First law of thermodynamics and Law of thermodynamics

First law of thermodynamics noun - The fundamental principle of physics that the total energy of an isolated system is constant despite internal changes.

Law of thermodynamics and first law of thermodynamics are semantically related. In some cases you can use "Law of thermodynamics" instead a noun phrase "First law of thermodynamics".

Law of thermodynamics noun - (physics) a law governing the relations between states of energy in a closed system.

First law of thermodynamics and law of thermodynamics are semantically related. Sometimes you can replace phrase "First law of thermodynamics" with "Law of thermodynamics", this phrases are similar.