categorize vs class

categorize is not a noun while class is a noun.

Word	Noun	Adjective	Verb	Adverb
categorize	No	No	Yes	No
class	Yes	No	Yes	No

As verbs, class is a hyponym of categorize; that is, class is a word with a more specific, narrower meaning than categorize:

Other hyponyms of categorize include assort, classify, separate, sort, sort out.

categorize (noun)	class (noun)
	education imparted in a series of lessons or meetings
	elegance in dress or behavior
	a collection of things sharing a common attribute
	people having the same social, economic, or educational status
	(biology) a taxonomic group containing one or more orders
	a body of students who are taught together
	a body of students who graduate together
	a league ranked by quality

categorize (verb)	class (verb)
place into or assign to a category	arrange or order by classes or categories