These were large kingdoms governed by very strong kings (monarchs) with nearly absolute power. E.g. Sokoto Caliphate and Borno Empire.

these were made up of small-centralised states. They are very similar with the large empire in terms of administration. They only differ in terms of size. Examples of such kingdoms are the Oyo, Ife and Benin Empires

These societies did not have a well- defined and complex centralised system of administration. Council of elders and age grade governed them. The system was characterised by separation of powers and checks and balances. Examples of such societies are Igbo and Tiv