windows serial communication C++
<p>I'm new to c++ and windows serial communication. Now i'm following microsoft <a href="https://msdn.microsoft.com/en-us/library/ff802693.aspx" rel="nofollow">link</a>., But there I don't know the meaning of following variables what's those variables do . Please help me to understand what the following variables.
Variables i dont have idea</p>

<ol>
<li><strong>ipBuf</strong></li>
<li><strong>dwRead</strong></li>
</ol>

<p>code </p>

<pre><code>DWORD dwRead;
BOOL fWaitingOnRead = FALSE;
OVERLAPPED osReader = {0};

// Create the overlapped event. Must be closed before exiting
// to avoid a handle leak.
osReader.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);

if (osReader.hEvent == NULL)
   // Error creating overlapped event; abort.

if (!fWaitingOnRead) {
   // Issue read operation.
   if (!ReadFile(hComm, lpBuf, READ_BUF_SIZE, &amp;dwRead, &amp;osReader)) {
      if (GetLastError() != ERROR_IO_PENDING)     // read not delayed?
         // Error in communications; report it.
      else
         fWaitingOnRead = TRUE;
   }
   else {    
      // read completed immediately
      HandleASuccessfulRead(lpBuf, dwRead);
    }
}
</code></pre>