The large panel system building is a building constructed of large, prefabricated concrete slabs. Such buildings are often found in housing development areas.

The Eastern Bloc, also known as the Communist Bloc (Combloc), the Socialist Bloc, and the Soviet Bloc, was the coalition of communist states of Central and Eastern Europe, Asia, Africa, and Latin America that were aligned with the Soviet Union and existed during the Cold War (1947–1991). These states followed the ideology of Marxism–Leninism, in opposition to the capitalist Western Bloc. The Eastern Bloc was often called the "Second World", whereas the term "First World" referred to the Western Bloc and "Third World" referred to the non-aligned countries that were mainly in Africa, Asia, and Latin America but notably also included former pre-1948 Soviet ally Yugoslavia, which was located in Europe.