This section of the Springer Tracts in Modern Physics series, titled "Point Defects in Metals I: Introduction to the Theory," is a comprehensive review of the theoretical and experimental aspects of point defects in metals. The book, edited by G. Leibfried and N. Breuer, is dedicated to the memory of Professor Dr. Günther Leibfried, a renowned physicist who made significant contributions to the field of lattice theory and its applications. The preface highlights the importance of understanding point defects in metals, noting that while there have been many conferences and discussions on the topic, a comprehensive and simple review was lacking. The authors aim to fill this gap by providing a detailed introduction to the basic theoretical concepts and methods, making the content accessible to graduate students and researchers. The book is structured into several chapters, covering topics such as harmonic approximation, linear response, lattice theory, continuum theory, and the transition from lattice to continuum theory. It also discusses statics and dynamics of simple single-point defects, scattering of neutrons and X-rays by crystals, probability distributions, and the properties of crystals with defects in small concentrations. The appendices provide additional mathematical and physical background, including Fourier transforms, vector and linear operator properties, and tensor transformations. The authors acknowledge the contributions of various colleagues and friends, and express their gratitude for the support and discussions that contributed to the development of the book. The preface also includes a dedication to Professor Leibfried, who passed away before the final version of the manuscript could be completed.This section of the Springer Tracts in Modern Physics series, titled "Point Defects in Metals I: Introduction to the Theory," is a comprehensive review of the theoretical and experimental aspects of point defects in metals. The book, edited by G. Leibfried and N. Breuer, is dedicated to the memory of Professor Dr. Günther Leibfried, a renowned physicist who made significant contributions to the field of lattice theory and its applications. The preface highlights the importance of understanding point defects in metals, noting that while there have been many conferences and discussions on the topic, a comprehensive and simple review was lacking. The authors aim to fill this gap by providing a detailed introduction to the basic theoretical concepts and methods, making the content accessible to graduate students and researchers. The book is structured into several chapters, covering topics such as harmonic approximation, linear response, lattice theory, continuum theory, and the transition from lattice to continuum theory. It also discusses statics and dynamics of simple single-point defects, scattering of neutrons and X-rays by crystals, probability distributions, and the properties of crystals with defects in small concentrations. The appendices provide additional mathematical and physical background, including Fourier transforms, vector and linear operator properties, and tensor transformations. The authors acknowledge the contributions of various colleagues and friends, and express their gratitude for the support and discussions that contributed to the development of the book. The preface also includes a dedication to Professor Leibfried, who passed away before the final version of the manuscript could be completed.