assortment vs indexing

assortment and indexing both are nouns.

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

As nouns, indexing is a hyponym of assortment; that is, indexing is a word with a more specific, narrower meaning than assortment:

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

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