By organization Maturana refers to the relations between components that give a system its identity, that make it a member of a particular type. Thus, if the organization of a system changes, so does its identity. By structure Maturana means the actual components and relations between components that constitute a particular example of a type of system. The organization is realized through the structure, but it is the structure that can interact and change. So long as the structural changes maintain the organization, the system's identity remains.

John Mingers, Self-Producing Systems: Implications and Applications of Autopoiesis. Contemporary Systems Thinking. New York: Plenum P, 1995