I mean the numerical order of degree. E.g. 6 is higher than 4, yet lower than 9; 20 is higher than than 16, yet lower than 23.
This changes if out of sign aspects are used in interpretaion. In my chart Saturn on 25* is behind and square Neptune on 1*, yet both in AIR signs.
I swear it works!
A pity that Samantha Bean has deleted her reply I saw last evening that provided a short yet very clear explanation of the difference that hit the nail firmly on the head.
In harsh aspects, if the quicker planet is on a lower degree than the slower planet (e.g. 6* square 9*), it hasn't yet 'jumped the hurdle', so to speak. There is something between the natal aspect that the faster planet (6*) comes up against and is challenged by the slower planet (9*) throughout life.
The faster planet may attempt to, and even 'deal with it' and become stronger through the plantetary interaction. Yet something lingers and it doesn't seem able to let go and put whatever the slower planet indicated behind it.
In the same harsh aspect, if the faster planet is on 9* square the slower planet on 6*, the same challenging situations could occur, yet the faster planet is not only able to 'deal with it' in their effect but is also able to 'get over it' by jumping the hurdle, so to speak. It can move on without anything lingering.
I hope that makes it more understandable.
I have 4 separate squares in my natal chart. Except for Saturn-Neptune, the faster planet is thankfully ahead in degree of the slower planet. Being part of my natural nature, the challenges in them have been there all my life. Yet I feel I've made headway in dealing with them.
Glad to have added a sprinkling of thought.