The Cyrillic script (/sɪˈrɪlɪk/ ⓘ sih-RI-lik) is a writing system used for various languages across Eurasia. It is the designated national script in various Slavic, Turkic, Mongolic, Uralic, Caucasian and Iranic-speaking countries in Southeastern Europe, Eastern Europe, the Caucasus, Central Asia, North Asia, and East Asia, and used by many other minority languages.
It's important to note that in Italic and Script style fonts a lot of Cyrillic letters have different forms from their Block counterpart.
And a guide for telling what language you're seeing.
