Internet is a global system of interconnected computer networks, which use the Internet protocol suite (TCP/IP) for linking devices worldwide. It includes public, private, business, academic and government networks that are interconnected by an array of wireless, electronic and optical networking technologies. The Internet consists of a wide range of information services and information resources, such as hypertext documents, electronic mail, applications of the World Wide Web, telephony and file sharing. The Internet communications infrastructure comprises of a system of software layers and hardware components, which control various aspects of its architecture. The Internet is a tool of modern society enabling social interactions, associations and activities. This book brings forth some of the most innovative concepts and elucidates the challenges and applications of Internet services. The ever-growing need of advanced Internet services is the reason that has fueled the research in this field in recent times. This book is a complete source of knowledge on the present status of this important area of study.