Knot theory has recently emerged as a productive field of study in both the physical and mathematical sciences. This book is concerned with the fundamental question of the classification of knots, and more generally the classification of arbitrary (compact) topological objects which can occur in the normal space of physical reality. The author explains his classification algorithm--using the method of normal surfaces--in a simple and concise way. The reader is thus shown the relevance of such traditional mathematical objects as the Klein bottle or the hyperbolic plane to this basic classification theory. The Classification of Knots and 3-Dimensional Spaces will be of interest to mathematicians, physicists, and other scientists who want to apply this algorithm to their research in knot theory.