A:Answer If you're going from PC-A into Capture card, and then USB into PC-B, then yes. PC-B will be the computer you run the software and stream on while you play on PC-A
But really, if you're just streaming whatever you're playing or doing on your PC, you can just run capture software to do that without any additional hardware needed. I recommend Streamlabs OBS, and you can link your twitch, youtube, facebook, whatever platform you stream on to it, and stream your desktop / PC games through it.