Key aspects of USCIS include:

Application processing: USCIS processes a wide range of immigration-related applications, petitions, and forms submitted by individuals seeking immigration benefits or status adjustments. This includes applications for permanent residency (green cards), citizenship, work authorization, travel documents, family-based visas, employment-based visas, refugee and asylum status, and other immigration benefits.
Adjudication of petitions: USCIS adjudicates petitions filed by U.S. citizens and lawful permanent residents on behalf of family members, as well as petitions filed by employers seeking to sponsor foreign workers for employment-based visas. USCIS officers review and evaluate each petition to determine eligibility and compliance with immigration laws, regulations, and policies.
Naturalization process: USCIS administers the naturalization process for individuals seeking to become U.S. citizens through the process of naturalization. This includes processing naturalization applications, conducting interviews, administering citizenship tests, and overseeing oath ceremonies for new citizens.
Immigration enforcement: While USCIS primarily focuses on processing immigration benefits and services, it also plays a role in immigration enforcement activities, such as investigating cases of immigration fraud, conducting interviews and background checks, and collaborating with other federal agencies to detect and deter immigration violations.
Customer service and outreach: USCIS provides customer service and assistance to individuals navigating the immigration system, including responding to inquiries, providing information and guidance on immigration processes and requirements, and offering resources and tools to help applicants understand their rights and responsibilities.