The Russian alphabet (both the modern version and the previous ones) is composed according to the phonetic principle - this means that each letter corresponds to one or another sound of the given language. In general, almost all existing writing systems adhere to this rule to a greater or lesser extent, except, for example, Chinese, which does not use the alphabet. An exception is also the unwritten languages of the various small indigenous peoples who inhabit our planet.
Writing systems for many other Slavic and non-Slavic languages were created on the basis of the Russian alphabet. In Russia, almost all national languages of the subjects of the Russian Federation (except for Ves and Karelian) have a Cyrillic script. Also, based on the Russian alphabet, alphabets are officially used in many countries of the former USSR, as well as in Bulgaria, Macedonia, Serbia, Montenegro, Bosnia and Herzegovina, and Mongolia. In a number of countries (Azerbaijan, Turkmenistan, Uzbekistan, Moldavia) in the early 90s, a transition to the Latin alphabet was made.