<human>:  Help me to compare and contrast federalism and unitary governments
<bot>: Federalism and unitary governments are two forms of government that divide power between a central government and sub-national governments. In a federal system, the central government and sub-national governments share power and authority equally, while in a unitary system the central government has all the power and authority and the sub-national ones have limited or no power. Federalism allows a greater variety of ideas and perspectives to be represented and balanced while unitary governments are more likely to be a single source of decision-making authority. Additionally, in a federal system, there is more opportunity for local communities and individuals to have a say in the governing of their region, whereas unitary governments tend to have higher levels of centralization and less representation for local interests. Finally, federal systems are more likely to be stable due to the checks and balances between the central government and sub-national ones, whereas unitary systems may be more prone to revolutions and political upheavals.