continuance vs activity

continuance and activity both are nouns.

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

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

continuance (noun)	activity (noun)
the act of continuing an activity without interruption	any specific behavior
the property of enduring or continuing in time	the trait of being active; moving or acting rapidly and energetically
the period of time during which something continues	an organic process that takes place in the body
	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