It can, but it doesn't have to. Basically I define backpacking as traveling lightly and getting work along the way. Like being a nomad. Imagine if you packed a few things into a backpack with some water and traveled around doing whatever work comes your way and eating with either the money from that work or at a home that you are temporarily staying in. That is what I define as backpacking. You can backpack through America without a tent. XD
Does that make sense?