One of the key concepts of systemic family therapy, which characterizes the dynamic structure of relationships. It is an integral, complexly organized unity in which all elements are interconnected and interdependent. This means that the condition and behavior of each family member is influenced by the condition and behavior of any other family member. The behavior and functioning of the elements of the family system cannot be understood in isolation, only in the context of general family rules, boundaries and patterns of interaction. The family system is always based on a positive relationship between its elements. The main forms of this relationship are love and respect.