smorgasbord vs aggregation

smorgasbord and aggregation both are nouns.

Word	Noun	Adjective	Verb	Adverb
smorgasbord	Yes	No	No	No
aggregation	Yes	No	No	No

As nouns, aggregation is a hypernym of smorgasbord; that is, aggregation is a word with a broader meaning than smorgasbord:

Other hypernyms of smorgasbord include accumulation, assemblage, collection.

smorgasbord (noun)	aggregation (noun)
an assortment of foods starting with herring or smoked eel or salmon etc with bread and butter; then cheeses and eggs and pickled vegetables and aspics; finally hot foods; served as a buffet meal	the act of gathering something together
a collection containing a variety of sorts of things	several things grouped together or considered as a whole