title: What is the HWND parameter in the Windows Procedure Functions?
body: <p>I was testing some Win32 apps with c++, and in this code:</p>
  <blockquote>
  <p>LRESULT CALLBACK WindowProc(</p>
  <p>_In_  HWND hwnd,</p>
  <p>_In_  UINT uMsg,</p>
  <p>_In_  WPARAM wParam,</p>
  <p>_In_  LPARAM lParam</p>
  <p>);</p>
  </blockquote>
  <p>Looking at this <a href="http://msdn.microsoft.com/en-us/library/windows/desktop/ms633573%28v=vs.85%29.aspx" rel="nofollow noreferrer">MSDN Documentation</a>, I couldn't really understand what the HWND is?</p>
  <p>It says: <code>A handle to the window.</code>. What does that mean?</p>