registration vs tune-up

registration and tune-up both are nouns.

Word	Noun	Adjective	Verb	Adverb
registration	Yes	No	No	No
tune-up	Yes	No	No	No

As nouns, tune-up is a hyponym of registration; that is, tune-up is a word with a more specific, narrower meaning than registration:

registration (noun)	tune-up (noun)
the act of enrolling	adjustments made to an engine to improve its performance
the act of adjusting something to match a standard	exercising in preparation for strenuous activity
(music) the sound property resulting from a combination of organ stops used to perform a particular piece of music; the technique of selecting and adjusting organ stops
a document certifying an act of registering
the body of people (such as students) who register or enroll at the same time