relaxation vs sleeping

relaxation and sleeping both are nouns.

Word	Noun	Adjective	Verb	Adverb
relaxation	Yes	No	No	No
sleeping	Yes	Yes	No	No

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

Other hyponyms of relaxation include bed rest, bedrest, laziness, lie-in, dormancy, quiescence, quiescency, leisure.

relaxation (noun)	sleeping (noun)
freedom from activity (work or strain or responsibility)	the suspension of consciousness and decrease in metabolic rate
the act of making less strict	quiet and inactive restfulness
a method of solving simultaneous equations by guessing a solution and then reducing the errors that result by successive approximations until all the errors are less than some specified amount	the state of being asleep
an occurrence of control or strength weakening
a feeling of refreshing tranquility and an absence of tension or worry
(physics) the exponential return of a system to equilibrium after a disturbance
(physiology) the gradual lengthening of inactive muscle or muscle fibers

relaxation (adjective)	sleeping (adjective)
	lying with head on paws as if sleeping