In total, the letters consist of twenty-two different kinds of orders or arrangements (סדרים, sedarim)... As you have already heard, each different function has its own particular root, and this root is organized into orders or arrangements that are fitted to the root in question and its intended function. The quality and number of levels in each of these various orders or arrangements is an individual matter depending upon the intended function of any given order. In the case of the letters, each individual letter is one of the various different orders or interconnected clusters of lights necessary to bring about action. Each letter is a unique root suited to the execution of the action that has to emerge from it.