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.
The major difference between bosses and leaders is that bosses create disharmony, reluctance and internal fighting which can make reaching the goal difficult while leaders provide encouragement, pride and cooperation which not only drives the business to reach the goal, but quite often surpasses the goal.