Visual Studio 2005 & POSIX threads

[nanodano]

I've been looking for information on threading, and I found information on POSIX pthreads. Apparently, Visual Studio 2005 does not have pthreads.h in their library. I did a search on the computer, and I found pthreadlocale.obj in the LIB directory. Does this object file have anything to do with pthread.h? I heard you can compile a class into object code(or maybe it was a .DLL) so people can't read your source, but it is still useable. Could it be possible that a .obj file has pthread stuff in it?

This is a quote from the pthread project site:
Win32 does not, and is unlikely to ever, support pthreads natively. This project seeks to provide a freely available and high-quality solution to this problem.

With this statement, I'm assuming pthreadlocale has nothing to do with the pthread I am interested in. Might anyone know what pthreadlocale.obj is used for?

Thank you for reading.

P.S. If anyone has a good explanation of the difference between .DLL, .OBJ, and .LIB files, it would clarify many things for me.