The "JD-VCC" thing is explained lower on the page under the "Optical Isolation" section. The eight relay board he has pictured is essentially the same as your relay board (although with six more relays).
"Normally Open" (NO) means that the contacts are open (no current passes through) when the relay is not energized or powered off, and "Normally Closed" (NC) is where there is continuity between the contacts when the relay is powered off. Going by your picture, to the left of the screw terminals the scribbles describe that the bottom screw of each set of three is the NC contact, the middle screws are the "Common", and the top screws are the NO contacts.