Publisher Summary This chapter provides an overview of the book for all them who are interested in lubricated wear, including the lubricant formulators, user industries, and basic researchers in tribology. Besides consolidation of the available information, the book is to strengthen the theory–practice interface. Such a focus identifies the gaps in knowledge that need to be filled and will be of interest to tribologists. Development of knowledge is a long-term goal and the industry will be interested in the more immediate improvements to practice. This is addressed in the book, and well-argued methodologies are suggested, which can ameliorate the present situation.