Windows-1251 (a.k.a. code page CP1251) is a popular 8-bit character encoding, designed to cover languages that use the Cyrillic script such as Russian, Bulgarian, Serbian Cyrillic and other languages. It is the most widely used for encoding the Bulgarian, Serbian and Macedonian languages. In modern applications, Unicode is a preferred character set.
Windows-1251 or code page CP1251 is a popular 8-bit character encoding, designed to cover languages that use the Cyrillic script such as Russian, Bulgarian, Serbian Cyrillic and other languages. It is the most widely used for encoding the Bulgarian, Serbian and Macedonian languages. In modern applications, Unicode is a preferred character set.
Source and more information: Windows-1251 on the English Wikipedia