activation vs activity

activation and activity both are nouns.

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

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

activation (noun)	activity (noun)
the activity of causing to have energy and be active	any specific behavior
making active and effective (as a bomb)	the trait of being active; moving or acting rapidly and energetically
stimulation of activity in an organism or chemical	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