Employment Based Immigration 

Permanent residency visas: Obtaining permanent residency based on employment is normally a three-part process:

First, you must file a PERM/Labor Certification Application with the USDOL. Second, you must file an I-140, EB-2 petition (Professional/Advanced Degree, Extraordinary Ability, NIW/National Interest Waiver) or EB-3 petition (Professional/Bachelor's Degree and Skilled Workers) with the USCIS. And third, you must apply for an adjustment of status (I-485) with the USCIS.

However, if you qualify for an EB-1 (Extraordinary Ability, Outstanding Professors and Researchers, and Multinational Executive and Manager Transferees) or EB-2 (NIW) you are able to skip step one and move directly to steps 2 and 3.