class period vs class

class period and class both are nouns.

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

class period (noun)	class (noun)
a regularly scheduled session as part of a course of study	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

class period (verb)	class (verb)
	arrange or order by classes or categories