Ok, I hope I can explain this clearly. The cable tv company has a cable
coming to my house and going under my porch. There it hits a cable splitter
with 2 lines going to 2 different rooms. The cable coming in is a single
"strand". One of the room lines is also a single "strand". The other is a
double "strand", but only 1 strand is connected to the splitter. I imagine
this is leftover from when cable boxes had A/B knobs. In the room, both
strands come out of the wall, but only 1 has a proper connector on it, the
other strand is just cut.

Will the 1 "strand" work like a single cable, or will it need to be
replaced?