The two type of changes are:
1. Independence
When a certain nation declared its independence, their territory is no longer belong to the country that colonize it. Which means that the national boundary undergone a change in ownership. Before the independence, it belonged to the country that colonize the nation. After the independence it belong to the nation itself.
Example: South American countries declared independence from Spanish Empire
2. State Annexes
During annexation, a certain territory is acquired by another country (could either be done through forces or consensual method). When annexation occurs, the national boundaries of the country that being annexed now belong to the nation that annexed it.
Example: When West Papua was acquired by Indonesia.
