Soto Zen (Soto-Shu)
Soto is the leading school of Zen Buddhism. It was initially founded in China as the Caodong lineage of the Chan school of Buddhism and was later imported to Japan in the thirteenth century by Dogen Zenji, after which it was called Soto Zen.
In the Soto school (曹洞宗) of Zen, Zazen, or sitting meditation, is the core of the practice. After all, Zazen was the vehicle of Buddha's Awakening. Shikantaza or "just sitting" is the essence of Soto Zen. There is no goal to be attained beyond the practice itself.
Soto Zen practitioners do not actively seek Enlightenment or Satori (the Zen Buddhism term for enlightenment), but rather they seek to fully experience every moment; that is, to be acutely aware of every action in the here and now. As Zen Master Taisen Deshimaru once said, "Zazen has no object, it is purposeless, it only brings us back to ourselves." One doesn't need to worry about Satori.
Even though Zazen is at the heart of Soto Zen, Soto Masters have never discarded the use of koans outside the practice of Zazen. Unlike the Rinzai koans that are very formal, Soto koans are more dynamic and sometimes represents the master's spontaneous answers to a question, instead of being a predetermined question or riddle. Everything can be a koan, not just a special question or a special phrase, but life itself.
Practitioners of Soto Zen believed that Rinzai koans had become a formal technique. They thought that by putting too much emphasis on koans, the students of Rinzai Zen would be distracted by the urge to find an "answer" to the riddles by using mental faculties or the intellect, which, they believed, was opposed to the intuitive nature of Zen.
Soto Zen's vision of Enlightenment, or Satori, is different than that of the Rinzai school. As opposed to what many people may think, in Soto Zen, Satori is not a special state of consciousness. It is simply a return to a human being's original condition. It can be compared to the consciousness of a newborn baby that has not been "contaminated" in any way; that is, a consciousness that is pure and in full harmony with the cosmos and the universe.
Learn more about Soto-Shu: Soto Zen Official site
If you're seeking to explore Zen or Buddhism more deeply, here is a list of my favourite Buddhist books that you can use to learn more about this ancient tradition.