He terms confederate, unitary, and federal all refer to what part of government?

The terms confederate, unitary, and federal all refer to terms confederate, unitary, and federal all refer to: Where the power of a government is located
All of the terms above is used to describe a country whose government power located in the CENTRAL of the government. If the country created several states, those states act solely on the command from the central government.

The  ancient egyptians  who  built the pyramids  may have been  able  to move massive stone blocks across the desert by wetting the sand in front of a contraption  built  to pull the heavy objects