Answer: The Book of Zohar was written on the level of the upper world and uses its terminology. At the same time, it uses the terminology of our world, although it means to express the upper forces and spiritual attributes that yield the outcomes such as a table, chair, man, tree, sun, etc. This is called the language of the branches.
In addition, The Book of Zohar uses the language of Kabbalah. In the upper world where there are no worldly names and terms, The Book of Zohar uses the pure physical mathematical language of Kabbalah.
From the Kabbalah Lesson in Russian 2/5/17