Citizenship refers to the process of becoming a U.S. citizen
Many times people do not realize that they are United States citizens. Derivative Citizenship is the process whereby the Immigration and Naturalization Service will give you a Certificate of Citizenship proving that you are a United States citizen.
There are many ways that people are considered to be United States citizens. Many times, it will help people significantly to be citizens of the United States. Sometimes people are put in deportation proceedings, and have very little hope of not being deported. In these situations, they must explore the possibility whether they are a United States citizen through derivative citizenship.
Additionally, it is usually considerably faster to obtain the Certificate of Citizenship rather than going through the Naturalization process.