While there is no universal terminology, your intuition is following the right direction. With a single knob, obviously it adjusts everything. You loosen it to place the head and tighten it when done.

Most dual action ballheads though have one knob for releasing the tightness on the ballhead and one for allowing separate rotation at the base. The point is to allow independent rotation so that the head does change tilt or pitch while panning. This makes panoramas easier as long as the tripod is level already.

With triple action ballheads, you get the same ones as dual action plus one to adjust friction on the ballhead system. Usually you can get a similar effect by controlling how much you loosen the main knob but friction control seems to have a more controllable and repeatable effect on friction.

Honestly, from the examples you linked to, there does not seem to be any difference other than the size and load capacity of the ballheads. Should look at Manfrotto instead, you will see that the knobs are just as expected. The triple action 468MGRC4 has 3 knobs, while the dual action MH057M0-RC4 has two. The latter has an additional switch to allow the head to tilt by 90° for portrait shooting. It just acts as a limiter to the ballhead motion.