The Abbasid Caliphate differed from others in that it did not have the same borders and extent as Islam. Particularly, in the west of the Caliphate, there were multiple smaller caliphates that existed in relative peace with them.
The major difference between the protist and the animal kingdom is protists are unicellular protozoans and unicellular & multicellular, but animals are multicellular animals.
Commonwealth vs State. The difference between commonwealth and state is only in the names with regard to the US states. Commonwealth is a term that is used to refer to countries that were once ruled by England and were a part of the British Empire. This is a loose grouping of more than 50 countries, many of which are republics in themselves owing no allegiance to the queen of Britain.