The term "Old Believer" refers to a group of Russian Orthodox Christians who rejected reforms introduced by the Russian Orthodox Church in the 17th century. These reforms, initiated by Patriarch Nikon, aimed to align Russian practices with those of the Greek Orthodox Church. Old Believers maintain traditional rituals and beliefs, emphasizing the importance of their historical practices. Old Believers faced persecution for their beliefs, leading many to migrate to remote areas or other countries. Today, they are recognized for their rich cultural heritage, including unique religious practices, art, and music, which continue to be preserved by communities around the world, such as in Siberia and North America.