This book is a compilation of reprint articles on one of the most intriguing phenomena in modern physics, the Quantum Hall Effect. Together with a detailed introduction by the editor, this volume is intended as a reference for students and research workers in condensed matter physics and for those with a particle physics background. The papers have been chosen with the intention of emphasizing the topological aspects of the Quantum Hall Effect and its connections with other branches of theoretical physics such as topological quantum field theories and string theory. The contents include sections on integer effect, fractional effect, effect of global topology, effective theories, edge states and non-Abelian statistics.