serial vs periodical

serial and periodical both are nouns.

Word	Noun	Adjective	Verb	Adverb
serial	Yes	Yes	No	No
periodical	Yes	Yes	No	No

As nouns, periodical is a hypernym of serial; that is, periodical is a word with a broader meaning than serial:

serial (noun)	periodical (noun)
a serialized set of programs	a publication that appears at fixed intervals
a periodical that appears at scheduled times

serial (adjective)	periodical (adjective)
pertaining to or occurring in or producing a series	happening or recurring at regular intervals
pertaining to or composed in serial technique
of or relating to the sequential performance of multiple operations
in regular succession without gaps