The concept of cybernetics as it is defined by Wiener means “the science of control and communication, in the animal and the machine”. It is all about coordination, regulation, and control in the biological sciences. The Principia Cybernetica adds the following:
Cybernetics is committed to an epistemological perspective that views material wholes as analysable without loss, in terms of a set of components plus their organization. Organization accounts for how the components of such a system interact with one another, and how this interaction determines and changes its structure. It explains the difference between parts and wholes and is described without reference to their material forms. The disinterest of cybernetics in material implications separates it from all sciences that designate their empirical domain by subject matters such as physics, biology, sociology, engineering and general systems theory. Its epistemological focus on organization, pattern and communication has generated methodologies, a logic, laws, theories and insights that are unique to cybernetics and have wide-ranging implications in other fields of inquiry.

The topic of cybernetics was popularized by George Ashby in 1956, who wrote the book 'An introduction to cybernetics'. For those who are interested, the complete book is available online at http://pespmc1.vub.ac.be/ASHBBOOK.html.