This is my understanding of the difference between these two qualities. Judgement stems from fear and is based upon the idea that there is only ONE RIGHT WAY. It demonstrates that the person who is judging does not yet have the understanding that we are souls and infinite, eternal spiritual fractals of God, experiencing and learning. Judgement comes from a place of lack and confusion, and conditional love and is an ego perspective.
Discernment on the other hand comes from your soul and is rooted in love. Your infinite knowing that all is well. When you are discerning, you are making choices that are right for YOU without the need to have anyone else make those choices. In truth, all choices are valid. Discernment allows everyone to make their own decisions based on their own needs, perspectives and belief systems. When you discern, you grant yourself and everyone else unconditional love. You use wisdom to create the appropriate, loving boundaries but do not require anyone else to be, say, act, do or believe as you do.
Which feels better to you?