This term means to be friendly and kind to each other in peaceful co-existence. You (友) in its ancient ideographic form consists of two hands extending in the same direction, metaphorically indicating common interest and offering a helping hand to each other. Shan (善) means to be gracious and kind. When these two Chinese characters are used together as in the current term, they denote a close and harmonious relationship among people, a bond that transcends blood ties. This kind of bond is based on the principle of righteousness commonly upheld by all parties involved. To date, as a hallmark of good character and ethical conduct, friendliness is still deemed as an essential element in the value system for building a harmonious and ideal society.

Friends are those who support each other if necessary. If they differ in principle, what can they depend on to help each other? ... Choosing friends should therefore be done with great care. That is the starting point for moral cultivation. Xunzi

A man of virtue selects a worthy individual first before making friends with him, whereas an ordinary man engages with people first before choosing those who would be beneficial to him. Wenzhongzi