The Internet of Things (IoT) has emerged as a transformative force in residential automation, enabling smart home systems that interconnect sensors, actuators, and computing infrastructure to deliver improved convenience, energy efficiency, and security. This paper presents a structured review of IoT-based smart home automation systems, synthesizing findings from five open-access research works covering system architectures, wireless communication protocols, hardware platforms, software frameworks, and cybersecurity. Key findings indicate that Wi-Fi and ZigBee dominate current deployments due to their complementary power and bandwidth profiles; fog computing is reshaping gateway architectures toward lower latency and greater resilience; ESP8266/ESP8285 microcontrollers and Raspberry Pi boards constitute the most widely adopted hardware platforms for cost-sensitive deployments; and cybersecurity particularly authentication, encryption, and device vulnerability management, remains the most critical unresolved challenge. Future directions including AI-driven automation, standardized interoperability, and privacy-preserving architectures are discussed.

Keywords— Internet of Things; smart home automation; Wi-Fi; wireless sensor networks.