This book serves as a foundation to the field of HCI, equipping readers with the necessary knowledge and skills to engage in this field. This book Discusses human functionalities and characteristics relevant to interaction, including sensory perception, attention and memory, language and communication, emotions, decision-making, as well as mental models, human error, and human actions. Explores the evolution of HCI design approaches and the role of social and organizational psychology in HCI Discusses key concepts and societal aspects of interactive technologies, such as user acceptance, ethics, privacy, and trust. Covers the historical background, contributing disciplines, essential concepts, and theories within the domain. This book will appeal to individuals interested in Human–Computer Interaction research and applications.