Citizenship certificates and Naturalization certificates are different documents. But both the documents can be used to prove that a person is a citizen of the United States of America.
A U.S. citizenship certificate is granted to a person who acquires or derives citizenship from his/her U.S. citizen parents. But a certificate of naturalization is granted to an immigrant who becomes a citizen of the United States through the naturalization process.
A Citizenship Certificate or Naturalization Certificate is used to prove the citizenship status of a person. You might need to prove your citizenship status when applying for Social Security benefits, driver’s license or learning permit, financial aid, employment, or a U.S. passport.
A person who was born outside the country to a U.S. citizen parent may obtain a citizenship certificate and use it to prove that he/she is a U.S. citizen. If you are eligible for a citizenship certificate you need to file the USCIS Form N-600, Application for Certificate of Citizenship.
An immigrant through the legal process called naturalization can also obtain U.S. citizenship. The person who seeks to become a U.S. citizen must be a Green Card holder and satisfy some more eligibility requirements. The permanent resident if eligible for Citizenship through Naturalization can file the application for naturalization and then appear for an interview.
The Green Card holder will have to take the English and the civics tests. After the application is approved and if the applicant is found to be eligible for U.S. citizenship, they will be required to take the Oath of Allegiance to America, at the naturalization ceremony. Then they will be granted a naturalization certificate and they may use that document to prove that they are a citizen of the country. Remember that only naturalized U.S. citizens will be granted naturalization certificates.
Holders of both the certificates will be granted U.S. citizenship rights including the right to vote and they can also obtain U.S. passports. Both the certificates serve a single purpose but the eligibility requirements to obtain the certificates are not the same. You need to file different forms to obtain these certificates.
A person who is eligible for a certificate of citizenship should not apply for naturalization to get the certificate but rather should apply for the citizenship certificate using Form N-600.
But you may use the USCIS Form N-565, Application for Replacement Naturalization/Citizenship Document, to replace both the certificates. You may file Form N-565, to replace your naturalization certificate or your citizenship certificate, if you had lost it or if it was destroyed.