With the ability to create seamless connectivity that can be automated, the Internet of Things (IoT) has transformed the way industries work, as well as how we live everyday. Yet the proliferation of IoTs has exposed glaring security flaws in their ecosystems, which implicate the use, the enterprise, and the policymaker comprehensively. Then this review will look at the landscape of IoT security in terms of emerging threats, vulnerabilities within the system and existing defense mechanisms. The study, examining key topics such as cybersecurity challenges, data breach prevention, and improvement of resilience for IoT, is a result of a thorough analysis of high impact research. It further points out the contributions of emerging technologies, such as blockchain, machine learning and edge computing in solving those problems. Moreover, since current research lacks metrics for securing resource constrained devices, ensuring interoperability and providing scalable defenses for heterogeneous environments, there are gaps identified in this review. This study proposes a strategic framework for future research and innovation to improve security of the IoT ecosystem and to foster trust and resilience in a world of increasing connectivity.