The use of physical hardware along with software and educational theory to aid learning is known as educational technology. It also seeks to improve performance through the creation, usage and management of appropriate technological resources and processes. Educational technology enables education to be individualized, thereby allowing the students to work and gain mastery of the curriculum at their own pace. There are several domains within this field such as learning theory, computer-based learning, m-learning and online learning. The designing of educational technology takes into consideration several pedagogical perspectives or learning theories. These perspectives are studied under E-learning theory. There are three main theoretical schools into which these perspectives are classified. These are behaviorism, constructivism and cognitivism. This book contains some path-breaking studies in the field of educational technology. It will also provide interesting topics for research which interested readers can take up. This book is appropriate for students seeking detailed information in this area as well as for experts.