employment vs activity

employment and activity both are nouns.

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

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

employment (noun)	activity (noun)
the occupation for which you are paid	any specific behavior
the act of using	the trait of being active; moving or acting rapidly and energetically
the act of giving someone a job	an organic process that takes place in the body
the state of being employed or having a job	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