Hermetic Qabalah is the foundation of Western esoteric schools of mysticism, magick, and the occult. It forms the foundation and underlying philosophy for their teachings and establishes the framework with which the magician can develop and evolve their abilities. This isn't to say there aren't other methods for obtaining such knowledge. Shamanism, Buddhism, Wicca, etc., there are numerous paths that lead to this goal. No one method is better or more important than another. What right have we to desecrate that which is held sacred in another's eyes? As a true magician, one should desire and seek wisdom of all sources. So that rather than a stubborn and myopic approach to the mystic realms, one may have a broad and sharpened sense of what truly exists, and be able to utilize that understanding to accomplish a great many things.
Within the teachings of the Golden Dawn, there are four different types of Qabalah:
1) Practical. This is the magician that prefers ritual and ceremonial magick. They'll take the extensive amount of time needed in preparation of their temple and the preliminary work as a means of reaching a higher state of consciousness in order to perform the magical working.
2) Literal. This magician is immersed in the knowledge-driven aspects of Qabalistic mysticism. The 3 various forms of sacred divination consist of Gematria, Notarikon, and Temurah.
3) Unwritten. The unwritten Qabalah is considered "mouth to ear." Meaning it is taught through oral tradition and verbal lessons. In ancient times, it was beneficial to teach the secret lessons of magic through whispers as to not have such subject matter written down and easily stolen or used to condemn the magician. Many secrets of occult knowledge are still passed from teacher to student in such a way.
4) Dogmatic. If you believe in a specific religion or philosophy, you believe in its dogma, or its doctrine. In Qabalistic terms, these would follow the teachings of religious tomes such as the Zohar, Sepher Yetzirah, the Bible, etc. I have witnessed many amazing accomplishments through the use of prayer and meditation alone!
While a magician doesn't have to strictly adhere to any one of these types of Qabalah, you will find yourself leaning more towards one type than another. I consider myself to be a ceremonial magician. Therefore I would fall into the practical application of mysticism. That stated, I also study Gematria and the Sepher Yetzirah. Don't limit yourself by categorizing your work. Instead, try aspects of all types to see what resonates with you and your abilities the best. A carpenter wouldn't build a house with only a hammer and nails. They would require many different tools to complete the job. This applies to ascending the magical path as well.