This book is not intended to be a cookbook for compilers, instead the authors' presentation reflects the special characteristics of compiler design, especially the existence of precise specifications of the subtasks. They invest effort to understand these precisely and to provide adequate concepts for their systematic treatment. This is the first book in a multivolume set, and here the authors describe what a compiler does, i.e., what correspondence it establishes between a source and a target program. To achieve this the authors specify a suitable virtual machine (abstract machine) and exactly describe the compilation of programs of each source language into the language of the associated virtual machine for an imperative, functional, logic and object-oriented programming language.