rudiments vs alphabet

rudiments and alphabet both are nouns.

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

As nouns, rudiments and alphabet are synonyms defined as:

rudiments and alphabet: the elementary stages of any subject (usually plural)

Other synonyms of rudiments include first principles.

rudiments (noun)	alphabet (noun)
the elementary stages of any subject (usually plural)	the elementary stages of any subject (usually plural)
a statement of fundamental facts or principles	a character set that includes letters and is used to write a language