Introduction
The US organizes migrants to the US based on either family relationships ("family-based immigration") or professional activities ("employment-based immigration"). The "Employment-Based" ("EB") categorires indicate the degree to which the US "prefers" those kinds of migrants over others, and thus the categories also are called Preference Categories. The following are the most common preference categories for employment-based permanent residence at Purdue
Priority Workers (EB-1)
Advanced-degree Professionals (EB-2)
Professionals holding basic degrees, Skilled Workers and other Workers (EB-3)