In its simplest form, a country is a defined area of land. However, country is also commonly used to refer to the state that controls the land or to refer to the nation that lives on the land. This is often additionally confused since the territory, state (government) and nation frequently share the same name. All three terms are commonly coterminous—where the boundaries of the territory matches that of the state's power and the nations area of occupation. However, there are many situations where the boundaries do not align. Populations have migrated; wars have destroyed and created new states; and unions have joined countries together. A country does not always cease to exist when occupied by another state or nation or broken up in to smaller states. The concept of the country survives even if the physical or political reality is different.