This book discusses the idea of distance and detour distance in graphs. The property of self centeredness in a graph is analysed using both these distances. The concept of detour eccentric sequences, detour distance degree sequences and detour distance distributions are defined. The book introduces new concepts like detour eccentric connectivity index and detour connective eccentric indicex. The structural nature of complement of a fuzzy graph is analyzed. Criterion for a fuzzy graph and its complement to be connected is derived. Fuzzy graph can be applied in numerous real life problems and also in the field of medicine. A new method is proposed, which helps in early detection of Autism spectrum disorder using fuzzy graphs.