Who, or what, exactly is the Holy Spirit?

"Spirit" represents the energetic component of creation. It's like metal being the main part of a car engine. Many contend that the Creator, through intent and emotion, set "Spirit" in motion to create the various realities or dimensions. Each dimension, of course, possessing its own unique laws of physics, for lack of a better description. In essence, it is not Father/Mother God (or Father/Son, if that is your belief) that actually creates but rather "Spirit" that does. But each are essential components in the creation process. The Creator makes the choice of what to create, down to the smallest detail, and then pes on the specifics to Spirit, who does the actual work by forming that creation.