Yichudim

The Zohar speaks of a specific form of Jewish meditation known as "Unifications or Yichudim".

There are two types spoken of in general.

A yichud M"AH U BAN and a YICHUD A"VA.

YICHUD MAH U BAN is the unification of one's emotions with action.

YICHUD AVA

This apparently is the process whereby a Kabbalist traces an object or concept in this physical world, up through the various levels of G-d's creative process of that object or ooncept. The goal of a unification to twofold. One, to uncover the inherent G-dliness in the subject that is being meditated on, and second, to bring the G-dliness "back home", so to speak.

That is to say. Once the G-dliness of the thing is uncovered. The kabbalist will endevour to conceptually understand how all the levels that once separated him and G-d are actually all one.

Sources: Zohar, Aryeh Kaplan, Gate of Unity by Dovber Schneuri