I-130 is ALWAYS the first step towards getting a GC for a relative. Whether they are abroad or in the USA. Approval of this form gives a spouse
K visa. On K-visa spouse enters into USA & then ADJUST STATUS using I-485.
I-485 is Status Adjustment Form, filed by people who are currently in the US,(e.g., when they enter with a K-1 or K-3 visa.).
However, in some instances, for people who are already in the USA, the preferred way is to file for I-130 and I-485 at the same time, that way both are approved concurrently and you do not have to wait 4-6 months for the I-130 to be approved and then file I-485.
While Adjustment of Status(I-485) is pending, spouse needs
I-131(Advanced Parole=AP) to go out of USA & needs
I-765(EAD) to work in USA.
However,Those who are authorized to work based on their nonimmigrant status (e.g. H-1B, L-1) can continue to work in their status without
EAD, as long as their status has not expired, if they so wish. And, certain nonimmigrant categories (H, L, V, K1/K3) can enter on a valid visa in their category instead of using
AP.
==============================================
Links for "New to Immigration" ppl in 1st post of this thread:-
http://www.immigrationportal.com/showthread.php?t=188386
==============================================