In Zen (Chan) Buddhism, the role of a teacher or master is highly valued and respected. They are seen as essential guides on the path to enlightenment, helping students deepen their understanding and practice of Zen teachings. The teacher-student relationship is considered to be crucial in the journey towards enlightenment.

First and foremost, a Zen teacher or master serves as a role model for their students. They embody the teachings of Zen through their actions, words, and way of life. This is known as "transmission without words," where the teacher's presence and behavior serve as an inspiration for students to follow in their footsteps.

A Zen teacher also plays the role of a mentor, offering guidance and support to their students. They provide instruction on meditation techniques, offer advice on how to overcome obstacles and challenges in one's practice, and help students deepen their understanding of Zen teachings. This guidance is crucial in helping students navigate their own unique paths towards enlightenment.

In Zen, the teacher-student relationship is based on mutual trust and respect. The teacher is seen as a compassionate and wise guide, while the student is expected to approach the teacher with an open mind and heart. This relationship is built on the foundation of the Four Noble Truths and the Eightfold Path, with the teacher guiding the student towards the ultimate goal of liberation from suffering.

Another important role of a Zen teacher is to challenge and provoke their students. This is done through the use of koans, which are paradoxical statements or questions that are meant to disrupt the student's logical thinking and lead them towards a deeper understanding of reality. The teacher may also use other methods such as physical gestures, shouts, or spontaneous actions to help students break through their conceptual thinking and experience direct insight.

Lastly, a Zen teacher or master serves as a spiritual friend to their students. They offer support, encouragement, and companionship on the journey towards enlightenment. This relationship goes beyond the traditional student-teacher dynamic and is based on a deep sense of connection and understanding between the two.

In conclusion, the role of a Zen teacher or master is multi-faceted and crucial in the practice and understanding of Zen teachings. They serve as role models, mentors, challengers, and spiritual friends to their students, guiding them towards the ultimate goal of enlightenment through direct experience and meditation.