discussion vs communication

discussion and communication both are nouns.

Word	Noun	Adjective	Verb	Adverb
discussion	Yes	No	No	No
communication	Yes	No	No	No

As nouns, communication is a hypernym of discussion; that is, communication is a word with a broader meaning than discussion:

discussion: an extended communication (often interactive) dealing with some particular topic
communication: the activity of communicating; the activity of conveying information

Other hypernyms of discussion include communicating.

discussion (noun)	communication (noun)
an exchange of views on some topic	something that is communicated by or to or between people or groups
an extended communication (often interactive) dealing with some particular topic	the activity of communicating; the activity of conveying information
	a connection allowing access between persons or places