Important world institutions, such as the United Nations (UN), the World Health Organization (WHO), the International Energy Agency (IEA), and the Organization for Economic Co-operation and Development (OECD), have publicly recognizing the highly interconnected nature of our world and therefore the relevance of systemic thinking and cybernetics as leading knowledge foundations to deal with the complexity of economic, social, and environmental issues. This recognition was the driving force of the Internet discussions held by participants to the World Organisation of Systems and Cybernetics 18th Congress, which last September 27 to 29(WOSC 2021). More than ever we needed to debate and develop current ontological, epistemological, and methodological approaches to the understanding of the future of humanity. WOSC organized this event in collaboration with the Russian Academy of Sciences (RAS). Scientists of this Academy together with scientists from all over the world made contributions to improving communications beyond particular nation states and regions toward the clarification of global issues like governance, health, education, technology, art, and others. Our aim in WOSC 2021 was bringing together scientists and researchers to collaborative debates at all levels from local communities to global societies. At the end of the Congress, scientists were invited to submit contributions to this Springer Nature book, along the following four themes: firstly, philosophical and methodological foundations for the development of the systems approach and cybernetics; secondly, the cybernetics of society, ecology and governance; thirdly, digital technologies and physical realities merging into a hybrid reality , and fourthly, the transdisciplinarity of systems sciences and cybernetics applied to the further development of knowledge areas, such as education, embodiment of social policies, and the arts. About 25 contributions were accepted for publication in this book. We see this as one of WOSC's important contribution to the scientific community around the world.