"Now, Let us talk about Yin Yang and ‘Teacher Student relationship’. The color white in the yin-yang symbol ☯ may also be seen as representing color of Knowledge or color of Light (also color for Goddess ‘Saraswati’ of knowledge in Hinduism). The color black may therefore represent Student or Learner which has some lack of Knowledge (Black is also symbolizing here the ‘darkness’ or ‘Absence of Light’). Both of them (Student and Teacher) complete the Teaching-Learning System (System again, here represents more than sum of its parts).
Now let us talk of ‘Black inside the White’ and ‘White inside the Black’ in the Yin Yang ☯ symbol. As the color ‘White’ is representing ‘Teacher’ here, we can explain it as following way-
There is Student (Learner) in every Teacher. Unless he or she (Teacher) learn continuously, he or she cannot survive for the long run. In other words, while teaching the students, Teachers can (and they do) learn continuously for the students and from the students. Similarly, within every student, there lies a teacher which is represented as 'White circle within the Black' part of Yin Yang symbol ☯. Also, many students that learn from the teachers; help their peers (Classmates/ Juniors/ Brother or Sisters) by teaching their peers to understand the concepts. By bringing some new or out-of-the-box perspectives in the classroom the 'Students' teach their ‘Teacher’ also. Other than these, some of the students become academicians/trainers/group-leads; with various teaching roles for life long.
So in this ‘Teacher Student’ system of this Universe, not only literally exact ‘Student’ or exact ‘Teacher’ may count. But also, all those come to this system; whom we teach something and from whom we learn something. This list comprises of literally anyone such as friends, family, colleagues or even unknown people. A nice example, which I personally observed from my pet cat when I was in class 10. I used to play with it and teaching sign language and various command. But in its short lifespan of one and half year, it taught me several things. I learned to acknowledging others you love, patience, and discipline (in timeliness way). So Teacher-Learner system is ubiquitous. We need to keep our mind and senses open to learn and observe it."-Arindum Mukhopadhyay