In “ Coming together federations” independent states come together on their own to form a bigger unit so that by pooling sovereignty and retaining identity they can increase their security while in “ Holding together” federation, a large country decides to divide its powers between the constituent states and the national government.
In “Coming together” federations, all the constituents states have equal powers whereas in “ holding together” federations, some units are granted special powers.PLEASE DO THUMBS UP...