Smart devices in a home automation system communicate using a variety of protocols, such as Wi-Fi, Bluetooth, and Zigbee. This allows devices like lights, thermostats, and security cameras to interact seamlessly over a centralized hub or cloud-based platform. Homeowners can control these devices remotely using smartphone apps or voice assistants. This interconnectivity enhances convenience, efficiency, and security, exemplifying the concept of the Internet of Things (IoT).