if u don't know what all these things are, go back and read books about windows programming and MFC.

MFC provides a strange and huge framework that encapsulates WinMain or _tWinMain. If u wanna find where WinMain is, please read MFC source code or read the book 《深入浅出MFC》by 侯俊杰（台湾）, there are a lot of links where u can download the whole book coz hou sir made it free.