Arabic alphabet vs alphabet

Arabic alphabet and alphabet both are nouns.

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

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

Arabic alphabet: the alphabet of 28 characters derived from Aramaic and used for writing Arabic languages (and borrowed for writing Urdu)
alphabet: a character set that includes letters and is used to write a language

Other hypernyms of Arabic alphabet include ABC's, ABC, ABCs, unicameral script.

Arabic alphabet (noun)	alphabet (noun)
the alphabet of 28 characters derived from Aramaic and used for writing Arabic languages (and borrowed for writing Urdu)	the elementary stages of any subject (usually plural)
	a character set that includes letters and is used to write a language