Answer:
To get a Green Card under EB2 - National Interest Waiver category, there are two independent steps. The first step is to file form I-140 along with a petition to verify that your employment has enough national interest to waive the otherwise required Labor Certification (PERM). After your I-140 is approved, you may file for Green Card using form I-485.
Many people prefer NIW for several reasons. First, you can self-petition. This means that you can file for Green Card
by yourself, without the consent or knowledge of your employer. Second, the NIW requirement is easier than EB-1 Alien of Extraordinary Ability. Third, with NIW, you can skip the Labor Certification process (PERM). Filing a Labor Certification is a burdensome and time consuming process.
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