multithread in windows

uintptr_t _beginthread( // NATIVE CODE  
   void( __cdecl *start_address )( void * ),  
   unsigned stack_size,  
   void *arglist   
);  
uintptr_t _beginthread( // MANAGED CODE  
   void( __clrcall *start_address )( void * ),  
   unsigned stack_size,  
   void *arglist   
);  
uintptr_t _beginthreadex( // NATIVE CODE  
   void *security,  
   unsigned stack_size,  
   unsigned ( __stdcall *start_address )( void * ),  
   void *arglist,  
   unsigned initflag,  
   unsigned *thrdaddr   
);  
uintptr_t _beginthreadex( // MANAGED CODE  
   void *security,  
   unsigned stack_size,  
   unsigned ( __clrcall *start_address )( void * ),  
   void *arglist,  
   unsigned initflag,  
   unsigned *thrdaddr   
);  

native code vs managed code -> c, c++ vs java, c#