I have doubt regarding the CreateThread() function in C++.

What is the importance of the threadId parameter in this function?

And are we able to create same thread( same name) using the same threadId. like

```
     DWORD threadId = 0;
     CreateThread(NULL, 0, Thread1, NULL,0, &threadId);
     CreateThread(NULL, 0, Thread1, NULL,0, &threadId);

```

This way is possible? What will be the value contain in the threadId? By doing the above codding , Is the second thread creation will over write the threadId value of first thread?