Russian is written using the Russian alphabet of the Cyrillic script; it distinguishes between consonant phonemes with palatal secondary articulation and those without—the so-called "soft" and "hard" sounds. Almost every consonant has a hard or soft counterpart, and the distinction is a prominent feature of the language. Russian is an East Slavic language of the wider Indo-European family. It is a descendant of Old East Slavic, a language used in Kievan Rus', which was a loose conglomerate of East Slavic tribes from the late 9th to the mid-13th centuries. From the point of view of spoken language, its closest relatives are Ukrainian, Belarusian, and Rusyn, the other three languages in the East Slavic branch.

Source: Wikipedia