The NVC is a permanent Immigrant Visa processing facility located in Portsmouth, NH which is operated by the Department of State. The NVC processes all approved immigrant visa petitions after they are received from the USCIS. This is where your case will be processed after it is approved by the USCIS. The NVC will hold the case until it is ready for adjudication by a consular officer abroad.
United States Citizenship and Immigration Services or USCIS. Formerly known as the Immigration & Naturalization Service or INS this is the government organization that processes all U.S. immigration petitions. You will file your initial petition (Form I-129F) with the USCIS.