Human-computer interaction deals with the research of the design and use of computer technology that is focused on the interfaces between people and computers. It observes the ways in which humans interact with computers. It also designs computer technologies that enable humans to interact with computers in new ways. The field of human-computer interaction combines the areas of design, media studies, computer sciences and several other fields. It primarily focuses on the methods of designing and implementing new computer interfaces. It also delves into methods for studying human computer use and its sociocultural implications along with methods for determining if the user is a human or a computer. This book presents the complex subject of human-computer interaction in the most comprehensible and easy to understand language. Some of the diverse topics covered in this book address the varied branches that fall under this category. It will provide comprehensive knowledge to the readers.