The Internet of Things (IoT) refers to the growing network of connected physical objects embedded with sensors, software and connectivity. While IoT has potential benefits, it also introduces new cyber security risks. This paper provides an overview of IoT security issues, vulnerabilities, threats, and mitigation strategies. The key vulnerabilities arising from IoT s scale, ubiquity and connectivity include inadequate authentication, lack of encryption, poor software security, and privacy concerns. Common attacks against IoT devices and networks include denial of service, ransom-ware, man-in-the-middle, and spoofing. An analysis of recent literature highlights emerging attack trends like swarm-based DDoS, IoT botnets, and automated large-scale exploits. Recommended techniques to secure IoT include building security into architecture and design, access control, cryptography, regular patching and upgrades, activity monitoring, incident response plans, and end-user education. Future technologies like blockchain, AI-enabled defense, and post-quantum cryptography can help strengthen IoT security. Additional focus areas include shared threat intelligence, security testing, certification programs, international standards and collaboration between industry, government and academia. A robust multilayered defense combining preventive and detective controls is required to combat rising IoT threats. This paper provides a comprehensive overview of the IoT security landscape and identifies areas for continued research and development.