From our daily lives, the Internet has become indispensable. We use the World Wide Web to obtain information, exchange information through social networks like Facebook and Twitter from, use e-mail and access within a company, in shielded intranets to the Internet technologies. In this course you learn to which technological bases the global Internet works. First the operating principles and technologies of local area networks (LANs) and wide area networks (WANs) are explained. Then the internet underlying TCP / IP reference model and its protocols, and numerous applications are presented generally understandable. The participants in this course is gaining a deep insight into the complex world of Internet technologies.