Some legal concepts you should know
Adjustment of Status
Adjustment of status is the process that a foreign national can use to apply for lawful permanent resident status (also known as applying for a Green Card). The process of adjustment of status is started when a person is present in the United States. This means that the applicant gets a Green Card without having to return to his home country to complete visa processing.
Once you are the beneficiary of an approved immigrant petition and an immigrant visa number is available, there are two ways to apply for lawful permanent resident status. If an applicant is outside of the United States, she/he may apply at a U.S. Department of State consulate abroad. This pathway is referred to as consular processing.
U.S. Citizenship and Immigration Services (USCIS) is an agency of the United States Department of Homeland Security (DHS) that administers the country's naturalization and immigration system. USCIS performs many duties, namely processing and adjudication of various immigration matters, including applications for work visas, adjustment of status, asylum, and citizenship. Additionally, the agency is officially tasked with safeguarding national security, eliminating immigration case backlogs, and improving efficiency.
A RFE is a Request for Evidence, this is a formal communication sent by the USCIS to petitioners for residency, citizenship, family visas, and employment visas.
Notice of Action
Notice of Action (NOA), Form I-797, is a letter mailed by USCIS to an immigrant petitioner to communicate the latest update and next steps for their petition. It's a form with information from USCIS, not a form that applicants fill out.
Notice of Approval
USCIS issues this base I-797 Notice of Action when it approves an application or petition. You may also hear people refer to it as an “approval notice.” The Form I-797 Notice of Action is an official letter of approval that can serve as proof of certain immigration benefits and may be used as evidence in some cases.