The nodes of the Moon in a birth chart describe an arc of evolution over the course of many lifetimes.
The South Node (SN) represents many lifetimes of conditioning about how the world is and should be like. The person’s families of origin and those who raise him or her in many lives (including this one) will have this theme emphasized in some way.
The North Node (NN), by contrast, represents what the chart holder has not been shown or modeled in many lifetimes but needs to learn. The NN is something almost no one wants to do, but integrating it is necessary for growth in this life. The souls in the family systems in many lifetimes (including this one) have agreed to have this be a blind spot, which naturally leaves something for the chart holder to have to learn on her or his own.
Weight and emphasis in the person’s life is always in the SN, while the NN might seem an empty or hollow point in the person’s life. A person will retreat to and rely on SN-related ways of living when stressed and challenged as, even if it’s not a happy place, it’s familiar. It’s a conditioned worldview that the person is born into in many lives, and so he or she will assume and expect the world to be that way. That person will behave accordingly, reinforcing the conditioned beliefs until balance occurs through integrating the ways of living shown by the NN.
In the 4-step karmic story I teach, the SN is the 2nd step and the NN is the 4th and final step. On the nodes houses and signs pages here, you’ll find the SN and NN treated in adjacent sections for each house and sign pair so you can see the contrast clearly.