Dual citizenship basically means that a person is a citizen of two different countries. He may be born in one country and be a naturalized citizen of the other. Perhaps he is of mixed parentage, and has inherited the dual citizenship of both the countries. He may have been born in one country and has acquired the citizenship of another by fulfilling residency and other requirements.
There are always those that want things like yesterday (meaning they do not want to wait for any reason) and are not that keen on waiting for the immigration process to be worked out. Then again, there are others who know that there is a value of waiting patiently for things to happen as they are meant to happen.