alphabet vs ABCs

alphabet and ABCs both are nouns.

Word	Noun	Adjective	Verb	Adverb
alphabet	Yes	No	No	No
ABCs	Yes	No	No	No

As nouns, alphabet and ABCs are synonyms defined as:

alphabet and ABCs: a character set that includes letters and is used to write a language

Other synonyms of alphabet include ABC's, ABC.

alphabet (noun)	ABCs (noun)
the elementary stages of any subject (usually plural)	a character set that includes letters and is used to write a language
a character set that includes letters and is used to write a language