calling together vs assembly

calling together and assembly both are nouns.

Word	Noun	Adjective	Verb	Adverb
calling together	Yes	No	No	No
assembly	Yes	No	No	No

As nouns, assembly is a hypernym of calling together; that is, assembly is a word with a broader meaning than calling together:

Other hypernyms of calling together include assemblage, gathering.

calling together (noun)	assembly (noun)
the act of convoking	the social act of assembling
	the act of constructing something (as a piece of machinery)
	a group of machine parts that fit together to form a self-contained unit
	a public facility to meet for open discussion
	a unit consisting of components that have been fitted together
	a group of persons who are gathered together for a common purpose