Yes there is a big difference, and it is all about the BMC the management controller of the board basically. There are other differences as well, but that is teh main one.
The DQ45CB, is definately not a server board.
It also depends what you classify as a server.
theoretically it cna be any computer that "serves", like the old p4 i have at home which is my "server" as that is where all my data is kept and the otehr compuetrs get anything tey need form that one.