This article discusses traditional models of federated states and the emergence of new federations after the second world war. An attempt was made to identify key signs of a federal state in modern conditions, taking into consideration new models of federalism, arising after the collapse of the colonial system. The author evaluates the extent to which previous signs of federalism correspond to modern conditions.The article highlights some of the features of the new federations (told only on significant features), but the author believes that selected common signs refer to all federations, despite the originality of some of them.