indexing vs assortment

indexing and assortment both are nouns.

Word	Noun	Adjective	Verb	Adverb
indexing	Yes	No	No	No
assortment	Yes	No	No	No

As nouns, assortment is a hypernym of indexing; that is, assortment is a word with a broader meaning than indexing:

indexing: the act of classifying and providing an index in order to make items easier to retrieve
assortment: the act of distributing things into classes or categories of the same type

indexing (noun)	assortment (noun)
the act of classifying and providing an index in order to make items easier to retrieve	the act of distributing things into classes or categories of the same type
	a collection containing a variety of sorts of things