What are the doctrines of the Chan (or Zen) School? What is the meaning of "Chan"?
禅宗的教义是什么？禅是什么意思？

"Chan" is short for "Channa", the Chinese transliteration of Jhāna (S. Dhyāna), meaning meditation or contemplation in tranquillity, also known as Chanding (Samādhi practice). This practice is to make the mind concentrate on one point of an object, and keep contemplating in order to become aware of the true nature of one's own mind. It is known as "Can Chan" in Chinese, so this school is called the Chan School, or Jhāna School. There are a number of types of "Chan", including Sāvaka Jhāna, Bodhisatta Jhāna, Step by Step Jhāna and Jhāna of Immediate Enlightenment. In Jhāna studies, there is a special Chinese subsect different from others, that is the Chan Sect, which claim "transmission of Dhamma without recourse to the scriptures". It is not the traditional gradual Jhāna, but the Jhāna of the Patriarch, which emphasizes "Direct pointing at the mind of the man, and the attainment of immediate enlightenment".
禅是禅那（Jhāna）的简称，汉译为静虑，是静中思虑的意思，一般叫做禅定。此法是将心专注在一法境上一心参究，以期证悟本自心性，这叫参禅，所以名为禅宗。禅的种类很多，有声闻禅、有菩萨禅、有次第禅、有顿超禅。禅学方面，在中国有一支异军特起，那就是所谓“教外别传”的禅宗。这个宗所传习的，不是古来传习的次第禅，而是直指心性的顿修顿悟的祖师禅。