Dual citizenship essentially means to be a citizen of two nations. This is the most common form of multiple citizenship by which a person is regarded as a citizen in more than one nation. There is nothing currently in international law preventing somebody from establishing citizenship in two different countries. As many countries automatically give citizenship to an individual upon birth in that country, it is then possible to receive an alternate citizenship in another country through marriage or other circumstances. Since there are processes in place such as naturalization that allow an individual to gain citizenship in a given country, they may also keep their citizenship in their home country as well. Dual citizenship allows you the rights of both of the countries for which you have this status and is considered to be undesirable by certain governments. Certain nations such as Japan may take away a former citizenship as they are not in favor of a dual citizenship through their government.