**1. Introduction**

Today, environmental and energy problems have become extremely serious and survival on a global scale. Scientists in all fields pay great attention to solving these problems. By this logic, the boom of recent decades, associated with the formation and development of nanotechnologies, including in relation to tribology and tribotechnics [1, 2].

It is noticeable that tribology has continuously developed into new phases. After opening in 1956, the effect of selective transfer (ST) ("zero-wear" effect) during friction, in tribology for the first time, was a basis to build the whole new paradigm of "friction without wear with minimal energy consumption", which was denied by all previous practical experience in operating movable coupling and by theoretical constructions of science of the friction and wear solids. At the same time, by the beginning of this century, the concept of "green tribology" was formed, which actually lists all the achievements in the study of the mechanisms of wearlessness (zero-wear) and super-anti-friction, as well as in the development of lubricants for their implementation in practice [3, 4]. In the 21st century and beyond, green tribology is expected to play an increasingly important role and become the key and strategies for solving a series of global problems in energy, environment and resources.

In recent years, there has been a rapid growth in research activities in green tribology field. A fairly large number of articles, world conference reports and academic books in related to this area have been published [2, 5–15]. However, there are still few publications that expounded the concepts, technological connotations, principles and disciplinary features of green tribology in precise, comprehensive definition and in an all-round way. The first scientific work completely devoted to green tribology, which emphasized the scientific rather than the economic and social aspects was published by M. Nosonovsky and B. Bhushan in 2010 [5].

Being a new field of tribology still in its infancy, an accurate understanding of the fundamentals of green tribology is important from both a scientific and practical point of view. In this regard, the aim of this work is to clarify the fundamental scientific and technological foundations of green tribology based on the analysis and generalization of the research achievements of green tribology.
