U.S Citizenship can be obtained either by birth or by a naturalization process. When obtained by a Naturalization process, you are allowed to live and work in the U.S permanently and you can't lose the status even by extended travel abroad. Once your citizenship is obtained, it is quite difficult to lose it. U.S Citizens are afforded certain benefits and privileges which include the privilege of being able to cast their vote in the U.S elections. Another benefit is that U.S citizens may petition for the permanent resident (PR) status of their immediate family members like parents, spouses, children, and siblings.