alphabet vs bedrock

alphabet and bedrock both are nouns.

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

As nouns, bedrock is a hypernym of alphabet; that is, bedrock is a word with a broader meaning than alphabet:

Other hypernyms of alphabet include basic principle, basics, fundamental principle, fundamentals.

alphabet (noun)	bedrock (noun)
the elementary stages of any subject (usually plural)	principles from which other truths can be derived
a character set that includes letters and is used to write a language	solid unweathered rock lying beneath surface deposits of soil