you know it is very important to understand these things,so I copy many links and screenshot as the following


https://technet.microsoft.com/en-us/library/cc749113(v=ws.10).aspx

wKiom1csCzKisrT7AAErLk3oDME500.png


https://technet.microsoft.com/en-us/library/cc766376(v=ws.10).aspx

wKiom1csC3fTLUR2AADF7jbG7j0730.png