One of the main components of IoT devices is its hardware part, as the very definition of IoT refers to the link between hardware and software, but how do you actually link these two, processors or computers only process the signals and computations digitally, but where do they actually pick up physical signals or provides the response which processor gives?? This work is done by Sensors and Actuators, read this section to know more about these physical components which form a major part of IoT.