The Alliance Navy is a Human military branch that only Earth's Military knows. The Alliance believes that Humans as a species aren't ready for aliens (though the Alliance is originated by Humans). The purpose of the Alliance is to explore and make allies with different alien races and species. The government, military, and the civilians of the alien races know of the Alliance, but knowing how Human civilians and government will react to aliens, the Navy is kept a secret. The Alliance navy and the Navy military branch are two separate branches.