procedure vs activity

procedure and activity both are nouns.

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

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

procedure (noun)	activity (noun)
a particular course of action intended to achieve a result	any specific behavior
a mode of conducting legal and parliamentary proceedings	the trait of being active; moving or acting rapidly and energetically
a process or series of acts especially of a practical or mechanical nature involved in a particular form of work	an organic process that takes place in the body
a set sequence of steps, part of larger computer program	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