В чем отличие между двумя классами?

State = ReqState.Ready; // SET STATE TO READY //
                    LastAction = Tick();
                    byte[] recvBuf = new byte[64];
                    Socket sck = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                    State = ReqState.Connecting; // SET STATE TO CONNECTING //
                    sck.Connect(RHost);
                    sck.Blocking = Resp;
                    State = ReqState.Requesting; // SET STATE TO REQUESTING //
                    sck.Send(buf, SocketFlags.None);
                    State = ReqState.Downloading; iRequested++; // SET STATE TO DOWNLOADING // REQUESTED++
                    if (Resp) sck.Receive(recvBuf, 64, SocketFlags.None);
                    State = ReqState.Completed; iDownloaded++; // SET STATE TO COMPLETED // DOWNLOADED++
                    if (Delay>0) System.Threading.Thread.Sleep(Delay);