Eastern Europe is the eastern part of the European continent. There is no consensus as to the precise area it refers to, partly because the term has a wide range of geopolitical, geographical, cultural, and socioeconomic connotations. There are "almost as many definitions of Eastern Europe as there are scholars of the region". A related United Nations paper adds that "every assessment of spatial identities is essentially a social and cultural construct."
One definition describes Eastern Europe as a cultural (and econo-cultural) entity: the region lying in Europe with main characteristics consisting in Byzantine, Orthodox, and some Turco-Islamic influences. Another definition was created during the Cold War and used more or less synonymously with the term Eastern Bloc. A similar definition names the formerly communist European states outside the Soviet Union as Eastern Europe. Historians and social scientists increasingly view such definitions as outdated or relegating, but they are still heard in everyday speech and used for statistical purposes.
More information on the Wikipedia page