Part 1: It is through the names that the lights come to execute their functions... For we see that the execution of all the different functions depends upon the holy names, of which there are many. All of the various names are understood as different combinations of interconnected lights (since each name is a unique combination of letters, and the letters are clusters of lights, as explained in Opening 20).
It is from these lights that the angels receive their power to act. At the root of the matter lies the fundamental idea set forth here: that it is the letters which bring the lights to execute their functions. The letters join together in various combinations, producing different names to execute the various functions. Each name possesses a unique power to execute a particular function, and it is through the different names that all the different functions are executed.
The Torah constitutes the sum total of all these names, as the sages said: “The whole Torah is made up of the names of the Holy One, blessed be He” (Zohar, Yitro 87a, and Ramban’s Commentary on the Torah, Introduction).