A form of many-valued logic in which the truth value of variables may be any real number between 0 and 1, including these two is termed as fuzzy logic. The basis of the fuzzy logic is the observation that people make decisions on the basis of imprecise and non-numerical information. Fuzzy logic has applications in many fields, ranging from control theory to artificial intelligence. Fuzzy models are used to mathematically represent vagueness and imprecise information. These models can represent, recognize, interpret and utilize the data and information that are vague. This book is a compilation of chapters that discuss the most vital concepts and emerging trends in the field of fuzzy logic. The various advancements in this field along with its engineering applications are glanced at herein. As this field is emerging at a rapid pace, the contents of this book will help the readers understand the modern concepts and applications of the subject.