letter of the alphabet vs alphabetic character

letter of the alphabet and alphabetic character both are nouns.

Word	Noun	Adjective	Verb	Adverb
letter of the alphabet	Yes	No	No	No
alphabetic character	Yes	No	No	No

As nouns, letter of the alphabet and alphabetic character are synonyms defined as:

letter of the alphabet and alphabetic character: the conventional characters of the alphabet used to represent speech

Other synonyms of letter of the alphabet include letter.

letter of the alphabet (noun)	alphabetic character (noun)
the conventional characters of the alphabet used to represent speech	the conventional characters of the alphabet used to represent speech