Final answer:
A confederation is a political system with a weak central authority deriving powers from state governments. Secession is the act of formally withdrawing from a larger group or organization. Annexation is when a political entity declares sovereignty over another territory.
Step-by-step explanation:
Confederation: A confederation is a political system in which a weak central authority derives its powers from state or provincial governments. The states within a confederation retain significant powers of an independent nation, such as maintaining a military force and making treaties with other nations. An example of a confederation is the Commonwealth of Independent States.
Secession: Secession is the act of formally withdrawing or separating from a larger group or organization. In the context of political entities, secession refers to a region or state declaring its independence from the existing governing body. An example of secession is the formation of the Confederate States of America by the Southern states during the American Civil War.
Annexation: Annexation occurs when one political entity declares sovereignty over another territory that was previously beyond its borders. It often happens when cities expand their territory, but when nations annex areas beyond their borders, there is usually opposition. An example of annexation is when Texas was annexed by the United States in 1845.