interrelation vs interrelatedness

interrelation and interrelatedness both are nouns.

Word	Noun	Adjective	Verb	Adverb
interrelation	Yes	No	No	No
interrelatedness	Yes	No	No	No

As nouns, interrelation and interrelatedness are synonyms defined as:

interrelation and interrelatedness: mutual or reciprocal relation or relatedness

Other synonyms of interrelation include interrelationship.

interrelation (noun)	interrelatedness (noun)
mutual or reciprocal relation or relatedness	mutual or reciprocal relation or relatedness