What is name check? When?

I read a lot about Name Check lately but I don't really understand it. My case is EB2. I140 was approved in 9/2004 and I did FP in 3/2005.My PD is 4/2002. I never got any request or infomation about Name Check. I have two question:
1, Is it because INS has not process my case or not everyone need Name Check? When the Name Check would start for my case?
2, When my I485 may start process.

Thank you very much.