The integration of Blockchain technology with the Internet of Things (IoT) has emerged as a significant research area focused on enhancing security, privacy, and trust in large-scale IoT networks. Research papers in this domain investigate blockchain-enabled frameworks for secure data sharing, device authentication, access control, and decentralized transaction management among heterogeneous IoT devices. Key contributions include lightweight consensus mechanisms, smart contract-based automation, scalability solutions for resource-constrained devices, and tamper-proof logging of IoT data. Recent studies also explore the combination of blockchain with edge and fog computing, AI-driven analytics, and federated learning to support real-time, secure, and decentralized IoT ecosystems. Challenges such as energy efficiency, latency, interoperability, and regulatory compliance are actively addressed to ensure practical deployment. By leveraging blockchain, IoT research aims to build resilient, transparent, and trustworthy networks for applications in smart cities, healthcare, supply chain management, industrial automation, and autonomous vehicles.