This schema posits that at any given moment, whatever is happening is occuring in each of four hierarchical realms, each one having its own meaning and consequences: Aztilut- the realm of ultimate emanation or spirit, Beriyah-the realm of Creation or thought, Yetzirah-the realm of formation or emotion, and Asiyah-the realm of Action. On the holiday of TuB'shvat, we eat fruits representing these four worlds: No fruit for Atzilut, fruit soft throughout for Briyah, fruit with pits for Yetzirah, and fruit with husks for Asiyah. The colors of the wine we drink for TuB'shvat are the colors associated with the four worlds.