This contributed volume offers a detailed review of the history, classification, synthesis, and physicochemical properties of deep eutectic solvents, highlighting their role as sustainable alternatives to traditional solvents. The book will examine their thermodynamic behaviors, micellization properties, toxicological profiles, and environmental benefits. Additionally, it will cover their applications in organic and inorganic synthesis, extraction techniques, and materials engineering while emphasizing their alignment with green chemistry principles. By presenting cutting-edge research and practical insights, this volume will provide a solid foundation for understanding the potential of DES in advancing sustainable industrial and scientific practices.