The rapid proliferation of the Internet of Things (IoT) has revolutionized various sectors, including healthcare, transportation, manufacturing, and smart homes, by enhancing connectivity and efficiency. However, this increased interconnectivity has also introduced significant cybersecurity challenges. This research paper explores the multifaceted nature of IoT security, focusing on key areas such as authentication, data encryption, regular updates, network segmentation, and the integration of emerging technologies like blockchain and artificial intelligence. It highlights critical security incidents, such as the Mirai botnet and Stuxnet worm, to underscore the urgency of implementing robust security measures. The paper also addresses the challenges posed by device heterogeneity, scalability, data privacy, and lifecycle management, and discusses future directions for IoT security, including standardization, regulatory frameworks, and user education. By prioritizing security throughout the IoT lifecycle, this paper aims to provide a comprehensive overview of strategies to safeguard a connected world.