e vs alphabetic character

e and alphabetic character both are nouns.

Word	Noun	Adjective	Verb	Adverb
e	Yes	No	No	No
alphabetic character	Yes	No	No	No

As nouns, alphabetic character is a hypernym of e; that is, alphabetic character is a word with a broader meaning than e:

e: the 5th letter of the Roman alphabet
alphabetic character: the conventional characters of the alphabet used to represent speech

Other hypernyms of e include letter, letter of the alphabet.

e (noun)	alphabetic character (noun)
the 5th letter of the Roman alphabet	the conventional characters of the alphabet used to represent speech
the base of the natural system of logarithms; approximately equal to 2.718282...