title: What does Get­Window­Thread­Process­Id return?
body: <pre class="lang-cpp prettyprint-override"><code>DWORD GetWindowThreadProcessId(
    HWND    hWnd,
    LPDWORD lpdwProcessId
  );
  </code></pre>
  <p>According to the docs, the return value is the identifier of the thread that created the window. What does that mean?</p>
  <p>I guess I'm just wondering what a threadID has got to do with the processID, what is it and what is it there for - does it validate the processID in some way? I want to just discard it because the processID is what I'm after.</p>