continuation vs activity

continuation and activity both are nouns.

Word	Noun	Adjective	Verb	Adverb
continuation	Yes	No	No	No
activity	Yes	No	No	No

As nouns, activity is a hypernym of continuation; that is, activity is a word with a broader meaning than continuation:

continuation (noun)	activity (noun)
the act of continuing an activity without interruption	any specific behavior
the consequence of being lengthened in duration	the trait of being active; moving or acting rapidly and energetically
a Gestalt principle of organization holding that there is an innate tendency to perceive a line as continuing its established direction	an organic process that takes place in the body
a part added to a book or play that continues and extends it	a process existing in or produced by nature (rather than by the intent of human beings)
	the state of being active
	(chemistry) the capacity of a substance to take part in a chemical reaction