What does the term "annexation" refer to?

The term "annexation" specifically refers to the action of adding territory to a larger entity, particularly in the context of a country extending its sovereignty over additional land. This practice has often occurred throughout history when one nation takes control of a region, either through military conquest, treaties, or other means of acquisition.

For example, the annexation of Texas by the United States in 1845 demonstrates how a territory was formally incorporated into the nation's land. This process can involve legal processes and recognition by other nations, but the core idea revolves around the expansion of territorial boundaries. The other concepts—such as establishing a protectorate or granting independence—do not accurately capture the essence of what annexation entails.