@guitarc I am not expert on NIW but it means National Interest Waiver. NIW does not require PERM filing but to qualify, one should have Advance Degree like Ph.D

@KhaiK these days all Employment based applicant have to appear for visa Interview and for that your file goes through various USCIS office (Nebraska/Texas - NBC Missouri - and your local USCIS office).  First transfer = file transferred to NBC from NE or TX (initial filing); second transfer = file transferred from NBC to your local USCIS office for interview.