The answers and the documentation provided by MSDN is the best, but I would like to add one typical case that I use a lot which requires the use of #pragma comment
to send a command to the linker at link time for example
#pragma comment(linker,"/ENTRY:Entry")
tell the linker to change the entry point form WinMain()
to Entry()
after that the CRTStartup
going to transfer controll to Entry()