(1) Ultralight backpacking.
(2) Essential backpacking. Bare bones adventure achieved by throwing a few things into a pack and just going.
Just going and leaving behind extra clothes, expensive backpacking gear, and clutter, keeping it as simple as possible and using your wits to make it work rather than money.
(3) Minimal travel. Hiking and camping over lengthy periods while using a minimum of food and leaving behind clothing, tents, and most other camping equipment.
"Dirtbagging," said Ed. "That's what they call ultralight backpacking, because soap is too heavy to carry. I decided to dirtbag it and just went. No frills. I just went."