There are 2 main types of ridgelines for tarps, continuous or separated. A continuous ridgeline is 1 continuous piece of cord that runs from tree to tree. Your tarp is attached to the cord by prusik knots or some type of hardware. You can hang your tarp over the top or underneath of the continuous ridgeline depending on your personal preference. A separated ridgeline is a cordage that attaches to both ends of the tarp and around the tree. You can use specialized hardware, carabines or just knots to attach the cord to the tarp. Once the cord is attached to the tarp it goes around the tree and is attached back to itself using knots or hardware.