What is a "Direct Method" in IoT?

A "Direct Method" in IoT refers to a function on the device that can be invoked by a back-end application. This capability allows applications to call predefined functions on the device to perform specific actions or retrieve information directly. For instance, an application might use a direct method to turn a device on or off, adjust settings, or trigger a specific operation that the device can perform.

This interaction model is essential for IoT scenarios where real-time control or query capabilities are required, enabling seamless communication between cloud applications and edge devices. By implementing direct methods, developers can facilitate interactive control of IoT devices, enhancing the overall user experience and operational efficiency.

The other options describe functionalities that do not align with the definition of a direct method. For example, callbacks for sensor data relate more to event-driven programming rather than direct invocation of device functions. Data aggregation methods pertain to the collection and summarization of data rather than invoking actions on devices. Lastly, protocols for data transmission focus on the means of communication between devices and applications, rather than the specific function invocation enabled by direct methods.