ABC's vs script

ABC's and script both are nouns.

Word	Noun	Adjective	Verb	Adverb
ABC's	Yes	No	No	No
script	Yes	No	Yes	No

As nouns, script is a hypernym of ABC's; that is, script is a word with a broader meaning than ABC's:

ABC's: a character set that includes letters and is used to write a language
script: a particular orthography or writing system

Other hypernyms of ABC's include character set.

ABC's (noun)	script (noun)
a character set that includes letters and is used to write a language	a written version of a play or other dramatic composition; used in preparing for a performance
	a particular orthography or writing system
	something written by hand

ABC's (verb)	script (verb)
	write a script for