Ten Sefirot as Process of Creation
According to Kabbalistic cosmology, Ten Sefirot (literally, Ten Numerations) correspond to ten levels of creation. These levels of creation must not be understood as ten different "gods" but as ten different ways of revealing God, one per level. It is not God who changes but the ability to perceive God that changes. While God may seem to exhibit dual natures (masculine-feminine, compassionate-judgmental, creator-creation), all adherents of Kabbalah have consistently stressed the ultimate unity of God. For example, in all discussions of Male and Female, the hidden nature of God exists above it all without limit, being called the Infinite or the "No End" (Ein Sof) - neither one nor the other, transcending any definition. The ability of God to become hidden from perception is called "Restriction" (Tsimtsum). Hiddenness makes creation possible because God can then become "revealed" in a diversity of limited ways, which then form the building blocks of creation.
Ten Sefirot and Physical Sciences
The Ten Sefirot mediate the interaction of the ultimate unknowable God with the physical and spiritual world. Some students of Kabbalah suggest that the Sefirot may be thought of as analogous to fundamental laws of physics. God's "Restriction" (Tsimtsum) within the spritual levels is often compared with the Big Bang in the lowest physical level. Just as the resulting gravity, electro-magnetism, strong nuclear force, and weak nuclear force allow for interactions between energy and matter, the Ten Sefirot allow for interactions between God and creation (Theory of Everything).
The Ten Sefirot are sometimes mentioned in the context of the Ten Dimensions that some physicists suspect the Superstring Theory may require.
Notable is the similarity between the concept in Kabbalah that the physical universe is made of divine light and the concept in Physics that it is made of energy.
Ten Sefirot as Process of Ethics
Divine creation by means of the Ten Sefirot is an ethical process. Examples: The Sefirah of "Compassion" (Chesed) being part of the Right Column corresponds to how God reveals more blessings when humans use previous blessings compassionately, whereas the Sefirah of "Overpowering" (Gevurah) being part of the Left Column corresponds to how God hides these blessings when humans abuse them selfishly without compassion. Thus human behavior determines if God seems present or absent. "Righteous" humans (Tzadikim) ascend these ethical qualities of the Ten Sefirot by doing righteous actions. If there were no "Righteous" humans, the blessings of God would become completely hidden, and creation would cease to exist. While real human actions are the "Foundation" (Yesod) of this universe (Malchut), these actions must accompany the conscious intention of compassion. Compassionate actions are often impossible without "Faith" (Emunah), meaning to trust that God always supports compassionate actions even when God seems hidden. Ultimately, it is necessary to show compassion toward oneself too in order to share compassion toward others. This "selfish" enjoyment of God's blessings but only if in order to empower oneself to assist others, is an important aspect of "Restriction", and is considered a kind of "golden mean" in Kabbalah, corresponding to the Sefirah of "Adornment" (Tiferet) being part of the "Middle Column".
In a numerological sense, the Tree of Sephiroth also has significance. Between the 10 Sephiroth run 22 channels or paths which connect them, a number which can be associated with the 22 letters of the Hebrew alphabet. In addition to each of this channels being assigned a letter of this alphabet, each path is also identified with one of the major trumps of the Tarot deck of symbolic cards [Minor Arcana: Stone(Pentacles), Sword(Swords), Cup(Cups), and Staff/Spear(Wands) of Destiny]. When combined with the 10 Sephiroth, these 22 paths make the number 32 which makes reference to the 32 Qabbalistic Paths of Wisdom and also the 32 degrees of Freemasonry.
To envision the tree, consider each of these ten spheres as being concentric circles with Malkuth being the innermost and all others encompassed by the latter. None of these are separate from the other, and all simply help to form a more complete view of the perfected whole. To speak simply, Malcuth is the Kingdom which is the physical world upon which we live and exist, while Kether, also call Kaether and Kaether Elyson is the Crown of this universe, representing the highest attainable understanding of God that men can understand.
Hypothetically there also exists an Eleventh Sephirah called Daath. It should be noted, however, that the first Qabbalists did not include any such sphere, making Daath a contested point of philosophical discussion. The Jewish Kabbalists that do accept this entity state that it is not a Sephirah, but rather that absence of one. In the Jewish tradition, the idea of an eleventh Sephirah is tantamount to blasphemy, as stated in the Sefer Yetzirah: "Ten Sephirot of Nothingness, ten and not nine, ten and not eleven.” [Ennead Mentation: The Nine Visitations of God 1-6 multiple sources, incl., Wikipedia]
Ennead Mentation: The Nine Visitations of God 1-6 Summary: web page