the paper deals with some particular issues about federalism. one of them and not so obvious is the conceptual one. it is remembered that federalism not always was treated with the same meaning. the mean characters are exposed jointly, signaling besides the different types of political associations inside which it is possible to include clearly the modern federations. additionally, the author devotes space to consider some other issues related, like the frequent appearance of assimetries and imbalances to the interior of federations. the former poses one of the biggest challenges to the operation and equilibrium in the contemporary scenarios where the federal form of governance matters. in the other side, the particular problem of fiscal imbalances open doors to the main issue of fiscal federal relations, which involves the central issues of expenditure assignment, tax assignment and transfers, as basic features of fiscal federalism. the paper includes some considerations about the argentinean scenario and concludes with some comments summarizing the general content of the note.