What does this mean in the log:the lines in bold

00:47:50:494   860   ETH: 03/13/18-00:47:50 - New job from us1.ethermine.org:4444
00:47:50:494   860   target: 0x0000000112e0be82 (diff: 4000MH), epoch 174(2.36GB)
00:47:50:494   860   gpu #0 dt 0.13 (0%, good)
00:47:50:494   860   gpu #1 dt 0.13 (0%, good)