Vfork error

I'm trying to study about vfork. when i used vfork, it shows the output as follows.

#include <sys/types.h>
#include <stdio.h>
#include <sys/wait.h>
void main()
{
        int pid;
        int status;
        pid = vfork();
        if(pid == 0)
        {
                printf("\nChild process\n");
               
        }
        else
        {
                printf("\n parent process\n");
               
        }
}

what does this mean?

If you have a look at the man page for vfork(), you should see it tells you that you should never return from the function in the child, or call exit() - call either _exit() or one of the exec() functions.

seems complicatted