The rapid advancement of the Internet of Things (IoT) has significantly transformed the way devices, systems, and services interact within modern digital ecosystems. When integrated with cloud computing, IoT systems gain enhanced capabilities in terms of scalability, storage, processing power, and real-time analytics. This analytical study explores the integration of IoT with cloud systems, focusing on architectural models, communication protocols, data management strategies, and system performance. It examines how cloud platforms enable efficient handling of massive data generated by IoT devices and facilitate intelligent decision-making through advanced analytics and machine learning techniques. The study also highlights key application domains such as smart homes, healthcare, industrial automation, transportation, and smart cities, where IoT-cloud integration plays a critical role. Furthermore, it addresses major challenges including data security, latency, interoperability, and bandwidth limitations, and discusses potential solutions such as edge computing, fog computing, and enhanced security frameworks. The findings emphasize that the synergy between IoT and cloud computing is essential for building scalable, reliable, and intelligent systems capable of supporting next-generation digital services and innovations.