detention vs penalisation

detention and penalisation both are nouns.

Word	Noun	Adjective	Verb	Adverb
detention	Yes	No	No	No
penalisation	Yes	No	No	No

As nouns, penalisation is a hypernym of detention; that is, penalisation is a word with a broader meaning than detention:

detention: a punishment in which a student must stay at school after others have gone home
penalisation: the act of punishing, or the infliction of a penalty

Other hypernyms of detention include penalization, penalty, punishment.

detention (noun)	penalisation (noun)
a punishment in which a student must stay at school after others have gone home	the act of punishing, or the infliction of a penalty
a state of being confined (usually for a short time)