The authors present the technical aspects of Asynchronous Transfer Mode (ATM) according to their relevance for developers and decision-makers. The listing of standards is limited to the essentials, with the main focus on fundamental, long-term valid statements about functions and mechanisms. ATM serves as a fast packet switching technology that forms the basis for broadband ISDN. Many modern telecommunications services involving data, image, and voice transmission are made possible by this. The authors emphasize the importance of presenting the various technical aspects of ATM while avoiding company-specific details.