In the context of U.S. immigration, what does the term 'removal' refer to?

The term 'removal' in the context of U.S. immigration refers specifically to the process of forcibly taking an alien back to their home country. This process typically occurs when an individual does not have a legal right to remain in the United States, such as being found inadmissible or removable due to violations of immigration law or crimes.

Contrary to the other choices, 'removal' focuses on the physical action of deporting someone who has been determined to be unlawfully present. Ending legal residency, removing a visa holder, or revoking citizenship, while related to immigration processes, do not encapsulate the full scope of what 'removal' entails. Removal is a legal, formal procedure executed through immigration courts or the U.S. Department of Homeland Security, ensuring that individuals who do not comply with U.S. immigration laws can be returned to their countries of origin. Thus, the emphasis is on the enforced return aspect, aligning with the selected answer.