Depending on your final application, measurement of distance can be quoted in many different forms but they all mean more-or-less the same thing. One meter can be: 1m, 100cm or 1000mm etc etc.
When it comes to tree climbing equipment and the measurement of units of force a similar principle applies.
daN (decaNewton) is a unit of force which is gaining favor over kN with climbing equipment manufacturers because many people find it easier to correlate with kg (mass).
Let's get a bit technical: 1kg mass acted upon by gravity applies a force of 9.81N or approximately 10N. So 10N is equal to 1daN which happens to equal 1kgf (approximately).
The next time you see 22kN you can think 2200daN or in terms of mass, 2200kgf.
To simplify matters even further some manufacturers have dropped the kN reference altogether in favor of daN (kg) - see Beal reference below. Teufelberger and the Treemagineers are another group applying the daN unit of force instead of kN.