In my cold room is a 4 inch diameter hole which I assume is there only
to let in the (cold) air. Is that the only thing that differentiates
the cold room from the rest of the basement? I dont notice anything
else.

I have finished the rest of the basement, so to finish the cold room
do I just finish it in the same way or are there special things to
take care of? How do I close the 4 inch hole and do I close it from
both inside and out?