I hope this gives you some better idea of what a round robin is. I like where you can pick the size of border you want to add. If you first square up your center, then add rounds that finished, are divisable by 3 , it is easier for the next person to figure out what to add.
A block swap is where you pick out the fabric you want to use in a quilt. Cut it into fat eights. Send the fat eights to everyone else that is in the swap. They each make a block for you of whatever design they choose and send it back to you. Everyone else sends you a fat eight. They make a block for you and send it back to you. Or there might be a theme block swap, such as Summer. Then you make 6 blocks of the same pattern and send it onto a hostess and she sends out the blocks back to senders and they get different blocks than what they sent in.