The unitary system of governing is a system in which the country is governed as a single entity. There are divisions in the country, but those divisions perform tasks that have been ordered and allowed by the central government.
The federal system of governing is a system in which the power in the country is divided between the federal states and the central government. They collaborate between each other, but the federal state has its own rights to perform certain things to certain level.
The confederate system of governing is a system in which the central government doesn't really have a lot of power, but instead the power lies mostly in the federal units who are governing themselves without having to ask for permission from the central government.
An example of unitary system is Hungary, an example for federal system is the United States of America, while example for confederate system were the Southern States of America.
