This report provides an overview of several key concepts related to information systems in the context of e-business. It begins by defining green computing and discussing the advantages and disadvantages of organizations adopting it, emphasizing the importance of reducing carbon footprint and energy costs. The report then delves into denial-of-service (DoS) attacks, providing a real-world example of an attack on the Australian Bureau of Statistics and its impact. Furthermore, the study examines the critical questions that should be addressed in a feasibility study before undertaking a new software development project. Finally, the report discusses paradigm shifts as the most radical form of organizational change, exploring the reasons why companies might undertake such shifts despite the potential for disruption. This report is available on Desklib, a platform providing various study tools for students.