The rapid evolution in development and implementation of IoT (Internet of Things) devices has transformed the way we interact with the digital world which offers unparalleled challenges. This research provides a comprehensive study of IoT technology, its various applications and exploring into the IoT cyber threat landscape, this paper serves as a roadmap for navigating the complex and dynamic IoT cyber threat landscape. The study begins by explaining the fundamental principles and architecture of IoT along with explanation of the complex web of interconnected devices in IoT ecosystems. It then proceeds to explore the multilayered applications of IoT across various domains like smart cities, agriculture, smart homes, industrial automation, etc. Along with expansion of IoT ecosystems, cyber threats and challenges are also increasing. An in-depth study of these potential cyber threats, vulnerabilities and risks related with IoT devices and IoT ecosystems has been done in the manuscript. Strategies for mitigating these cyber threats are discussed which encompasses both technical and policy-oriented approaches and also highlights the evolving regulatory landscape surrounding IoT security, emphasizing the need for standardized frameworks and best practices to ensure a resilient and secure IoT infrastructure. The study of emerging trends and technologies shaping the future of IoT such as edge computing, artificial intelligence, machine learning and blockchain along with their implementation for enhancing security and mitigation strategies. The interdisciplinary domain of IoT requires collaboration between researchers, manufacturers, stakeholders and policymakers.