Centralization of power is the basic feature of a unitary government.
In a unitary government, all powers are concentrated in the hands of the central government. This means that the central government has the power to make decisions and policies that affect the entire country, and all other levels of government, such as regional or local governments, are subordinate to the central government.
Centralization of power in a unitary government allows for more efficient decision-making and policy implementation, as the central government is in control of all resources and has a better overview of the entire country. However, it can also lead to a lack of autonomy and representation for regions or localities that may have different needs or perspectives.
In contrast, federalism is characterized by a sharing of power between the central government and regional or local governments. A confederation is a looser form of federalism, where the central government has limited powers and the regional or local governments have more autonomy. A presidential system is a type of government where the president is both the head of state and head of government, and is elected separately from the legislature.