Russian vs Slavic

Russian and Slavic both are nouns.

Word	Noun	Adjective	Verb	Adverb
Russian	Yes	Yes	No	No
Slavic	Yes	Yes	No	No

As nouns, Slavic is a hypernym of Russian; that is, Slavic is a word with a broader meaning than Russian:

Other hypernyms of Russian include Slavic language, Slavonic, Slavonic language.

Russian (noun)	Slavic (noun)
the Slavic language that is the official language of Russia	a branch of the Indo-European family of languages
a native or inhabitant of Russia

Russian (adjective)	Slavic (adjective)
of or pertaining to or characteristic of Russia or its people or culture or language	of or relating to Slavic languages