The dreamer and the dreamed ( question )

I am currently reading tales of power. Don Juan, with the aid of Genaro, begins to teach Carlos about the “ Dreamer & the Dreamed. “ However, unless I missed something , there was never really a concrete definition given as to what this phrase meant ( the dreamer and the dreamed ). The chapter where it is most heavily referenced is also the one where the double is heavily discussed and genaro gives insight to his initial experiences where he would reach lucidity in dreams, and directly witness his sleeping body while in his double.

I really wanted to know exactly what the dreamer and the dreamed meant but I seemed to be stumped. I want to make sure I don’t miss anything.

Is the dreamer and the dreamed a way of describing the doubles activity while in a state of lucidity, while the physical body is inactive and sleeping ?

Any help would be most appreciated.