Part 1: The Sefirot can shine with an abundant radiation of light or with diminished radiation. What this means is as follows: Since the Supreme Will wanted to display His simple powers by way of light, the revelation may be lesser or greater, since one light may shine only a little, whereas another may shine more powerfully. And this is what we see: Sefirot and Partzufim. As Sefirot, they shine with little light, but as Partzufim, they shine with abundant light (see below, Opening 17 on Sefirot and Partzufim).
When they shine as Partzufim, more details are revealed; as Sefirot, fewer parts are seen. So too there are variations in terms of the power and influence of individual Sefirot. Sometimes a Sefirah may shine with little light and little power (during the period of exile): this is known as “smallness” (קטנות, katnut, “smallness”, also “childhood”). At other times the Sefirah may shine with great power (after the redemption): this is known as “greatness” or “maturity” (גדלותgadlut).