Answer: "Zivug" is a connection according to the equivalence of form, the similarity of properties. This action is not based on what each of us used to be, but rather on how similar to each other we have become after corrections.
At first, we were completely separated and opposite. Then we performed corrections, and to the measure of these corrections we come to a "Zivug" (unity, adhesion).
Question: What is "Parsa"?
Answer: "Parsa" is a partition which separates the receiving desires from bestowing ones by the force of Bina. A person himself has to wish for such division to take place within him. And then he attracts the force of Bina, bestowal, the force of the Creator, so that it will protect and save him by separating bestowal and reception within him. This is called "to distinguish day from night, light from dark."
From the 3rd part of the Daily Kabbalah Lesson 1/20/2011, Talmud Eser Sefirot