An unrooted clone is a fresh cutting taken from a mother plant with no root system yet. A rooted clone has been in a rooting medium for 7 to 14 days and has developed white, healthy roots pushing through the cube.
Rooted clones are what most growers want. They're ready to transplant, they establish faster in your grow, and they've already survived the hardest part of the cloning process. You see exactly what you're getting — root mass, leaf color, stem structure. No guessing. No 10-day wait to find out whether the cut was viable in the first place.
Unrooted cuttings are cheaper and more portable, but they carry significant risk. Shipping stresses unrooted cuts hard, and between 10 and 30 percent commonly fail to root even under ideal conditions. You also need the full propagation setup ready to go — dome, heat mat, dialed environment, rooting hormone — from the moment the box arrives.
Unless you're running a controlled propagation setup and already know your way around a cloning tray, stick with rooted clones. The failure rate and lost two weeks are rarely worth the savings on an unrooted cut.