While rational homotopy theory is remarkably computational and simpler than ordinary homotopy theory, it is exactly this simplicity which makes it possible to address a number of fundamental questions in geometry and homotopy theory. The three main objectives of this book are:

* to provide a coherent, self-contained, and userfriendly introduction to the tools and techniques of rational homotopy theory

* to provide an account of the main structural theorems with proofs that are often new or much simpler than the original versions in the literature

* to illustrate both the use of technology and the consequences of the theorems in a rich variety of examples.

It should be emphasized that this book is about topological spaces and that examples and applications given throughout the book are largely drawn from topology. The reader should have a basic knowledge of the fundamental group and singular homology.