A Denial from USCIS means the application or petition will not be granted, and the immigration benefit they applied will not be approved. A denial notice will be sent to applicants or petitioner that include
A brief introduction of the immigration benefit they applied
A description that describe what criteria they must meet to be eligible for the benefit
A discussion that explain how the evidence fails to meet the requirement
A conclusion about the decision to deny the petition and their option to file a motion to reopen or reconsider the case or appeal the decision.
What are the options if I receive a denial notice from USCIS?
You either failed to provide the supporting documents or your situation are not consider eligible on the immigration benefits you applied. In the denial notice letter, it normally states that there are 30 days to appeal the decision. Based on the reason of denial and your case status, there are two options:
File an appeal or a motion. Which means you request to a different authority of the USCIS office that issued your denial to review the decision again. You can choose this route when you believe that your eligibility is correct and evidence you provide is sufficient, they did not review your case correctly and made the wrong judgement.
Start a new petition. Appeal and motion might be difficult and time-consuming in most of circumstances. Start a new petition may be faster sometime.