The Cyrillic alphabet is used for writing many different languages, including:
* Slavic languages: Russian, Ukrainian, Belarusian, Bulgarian, Serbian, Macedonian, Montenegrin, Slovene, Czech, Slovak, Polish (historically)
* Non-Slavic languages: Mongolian, Kazakh, Kyrgyz, Uzbek, Turkmen, Azerbaijani, Tajik, Bashkir, Chuvash, Yakut, Abkhaz, Ossetian, etc.
It's important to remember that an alphabet is just a system of writing. A language is a system of communication that includes pronunciation, grammar, and vocabulary.